Mol Biosyst [JOURNAL]
Sun
200 papers
Characterizing the structure-function relationship reveals the mode of action of a novel antimicrobial peptide, P1, from jumper ant Myrmecia pilosula.
Tseng TS, Tsai KC, Chen C
Mol Biosyst · 2017 Jun · PMID 28470277 · Publisher ↗
Microbial infections of antibiotic-resistant strains cause serious diseases and have a significant impact on public health worldwide, so novel antimicrobial drugs are urgently needed. Insect venoms, a rich source of bioa...
Microbial infections of antibiotic-resistant strains cause serious diseases and have a significant impact on public health worldwide, so novel antimicrobial drugs are urgently needed. Insect venoms, a rich source of bioactive components containing antimicrobial peptides (AMPs), are attractive candidates for new therapeutic agents against microbes. Recently, a novel peptide, P1, identified from the venom of the Australian jumper ant Myrmecia pilosula, showed potent antimicrobial activities against both Gram-negative and Gram-positive bacteria, but its structure-function relationship is unknown. Here, we used biochemical and biophysical techniques coupled with computational simulations to explore the mode of action of P1 interaction with dodecylphosphocholine (DPC) micelles as a model membrane system. Our circular dichroism (CD) and NMR studies revealed an amphipathic α-helical structure for P1 upon interaction with DPC micelles. A paramagnetic relaxation enhancement approach revealed that P1 orients its α-helix segment (F6-G14) into DPC micelles. In addition, the α-helix segment could be essential for membrane permeabilization and antimicrobial activity. Moreover, the arginine residues R8, R11, and R15 significantly contribute to helix formation and membrane-binding affinity. The lysine residue K19 of the C-terminus functionally guides P1 to interact with DPC micelles in the early interaction stage. Our study provides insights into the mode of action of P1, which is valuable in modifying and developing potent AMPs as antibiotic drugs.
Reconstruction and analysis of the lncRNA-miRNA-mRNA network based on competitive endogenous RNA reveal functional lncRNAs in rheumatoid arthritis.
Jiang H, Ma R, Zou S … +3 more , Wang Y, Li Z, Li W
Mol Biosyst · 2017 Jun · PMID 28470264 · Publisher ↗
Rheumatoid arthritis (RA) is an autoimmune disease with an unknown etiology, occurring in approximately 1.0% of general population. More and more studies have suggested that long non-coding RNAs (lncRNAs) could play impo...
Rheumatoid arthritis (RA) is an autoimmune disease with an unknown etiology, occurring in approximately 1.0% of general population. More and more studies have suggested that long non-coding RNAs (lncRNAs) could play important roles in various biological processes and be associated with the pathogenesis of different kinds of diseases including RA. Although a large number of lncRNAs have been found, our knowledge of their function and physiological/pathological significance is still in its infancy. In order to reveal functional lncRNAs and identify the key lncRNAs in RA, we reconstructed a global triple network based on the competitive endogenous RNA (ceRNA) theory using the data from National Center for Biotechnology Information Gene Expression Omnibus and our previous paper. Meanwhile, Gene Ontology (GO) and pathway analysis were performed using Cytoscape plug-in BinGO and Database for Annotation, Visualization, and Integration Discovery (DAVID), respectively. We found that the lncRNA-miRNA-mRNA network was composed of 7 lncRNA nodes, 90 mRNA nodes, 24 miRNA nodes, and 301 edges. The functional assay showed that 147 GO terms and 23 pathways were enriched. In addition, three lncRNAs (S5645.1, XR_006437.1, J01878) were highly related to RA, and therefore, were selected as key lncRNAs. This study suggests that specific lncRNAs are associated with the development of RA, and three lncRNAs (S5645.1, XR_006437.1, J01878) could be used as potential diagnostic biomarkers and therapeutic targets.
A novel computational model based on super-disease and miRNA for potential miRNA-disease association prediction.
Chen X, Jiang ZC, Xie D … +4 more , Huang DS, Zhao Q, Yan GY, You ZH
Mol Biosyst · 2017 May · PMID 28470244 · Publisher ↗
In recent years, more and more studies have indicated that microRNAs (miRNAs) play critical roles in various complex human diseases and could be regarded as important biomarkers for cancer detection in early stages. Deve...
In recent years, more and more studies have indicated that microRNAs (miRNAs) play critical roles in various complex human diseases and could be regarded as important biomarkers for cancer detection in early stages. Developing computational models to predict potential miRNA-disease associations has become a research hotspot for significant reduction of experimental time and cost. Considering the various disadvantages of previous computational models, we proposed a novel computational model based on super-disease and miRNA for potential miRNA-disease association prediction (SDMMDA) to predict potential miRNA-disease associations by integrating known associations, disease semantic similarity, miRNA functional similarity, and Gaussian interaction profile kernel similarity for diseases and miRNAs. SDMMDA could be applied to new diseases without any known associated miRNAs as well as new miRNAs without any known associated diseases. Due to the fact that there are very few known miRNA-disease associations and many associations are 'missing' in the known training dataset, we introduce the concepts of 'super-miRNA' and 'super-disease' to enhance the similarity measures of diseases and miRNAs. These super classes could help in including the missing associations and improving prediction accuracy. As a result, SDMMDA achieved reliable performance with AUCs of 0.9032, 0.8323, and 0.8970 in global leave-one-out cross validation, local leave-one-out cross validation, and 5-fold cross validation, respectively. In addition, esophageal neoplasms, breast neoplasms, and prostate neoplasms were taken as independent case studies, where 46, 43 and 48 out of the top 50 predicted miRNAs were successfully confirmed by recent experimental literature. It is anticipated that SDMMDA would be an important biological resource for experimental guidance.
The multi-output incoherent feedforward loop constituted by the transcriptional regulators LasR and RsaL confers robustness to a subset of quorum sensing genes in Pseudomonas aeruginosa.
Bondí R, Longo F, Messina M … +4 more , D'Angelo F, Visca P, Leoni L, Rampioni G
Mol Biosyst · 2017 Jun · PMID 28466892 · Publisher ↗
Quorum sensing (QS) is an intercellular communication system which controls virulence-related phenotypes in the human pathogen Pseudomonas aeruginosa. LasR is the QS receptor protein which responds to the signal molecule...
Quorum sensing (QS) is an intercellular communication system which controls virulence-related phenotypes in the human pathogen Pseudomonas aeruginosa. LasR is the QS receptor protein which responds to the signal molecule N-(3-oxododecanoyl)homoserine lactone (3OC-HSL) and promotes signal production by increasing the transcription of the 3OC-HSL synthase gene, lasI. LasR also activates the expression of other genes, including rsaL, coding for the RsaL protein which acts as a transcriptional repressor of lasI. Direct gene activation and RsaL-mediated gene repression, both exerted by LasR on the expression of the output gene lasI, generate a regulatory network motif known as the type 1 incoherent feedforward loop (IFFL-1) that governs 3OC-HSL production. In addition to lasI, RsaL directly represses a set of LasR-activated genes; hence, the IFFL-1 generated by LasR and RsaL is a multi-output IFFL-1. Here we demonstrate that the multi-output IFFL-1 constituted by LasR and RsaL confers robustness with respect to fluctuations in the levels of LasR to the phenotypes controlled by both these transcriptional regulators (e.g. 3OC-HSL synthesis and pyocyanin production). In contrast, other virulence-related phenotypes controlled by LasR but not by RsaL (e.g. elastase and protease production) are sensitive to changes in LasR levels. Overall, the multi-output IFFL-1 generated by LasR and RsaL splits the QS regulon into two distinct sub-regulons with different robustness with respect to LasR fluctuations. This emerging regulatory property enhances the phenotypic plasticity of P. aeruginosa, thus contributing to its adaptation to changing environments.
Metabolic profiling of asthma in mice and the interventional effects of SPA using liquid chromatography and Q-TOF mass spectrometry.
Su L, Shi L, Liu J … +3 more , Huang L, Huang Y, Nie X
Mol Biosyst · 2017 May · PMID 28463380 · Publisher ↗
Asthma is a chronic inflammatory lung disease that leads to 250 000 deaths annually. There is a need to better understand asthma by identifying new pathogenic molecules. We conducted a liquid-chromatography time-of-fligh...
Asthma is a chronic inflammatory lung disease that leads to 250 000 deaths annually. There is a need to better understand asthma by identifying new pathogenic molecules. We conducted a liquid-chromatography time-of-flight mass spectrometry (LC-Q-TOF-MS)-based metabolomics study to test for asthma and investigate the interventional mechanisms of surfactant protein A (SPA) in OVA-induced asthma mice. The results revealed that asthma disturbed 32 metabolites in 9 metabolic pathways. After SPA treatment, the metabolomics profile found in asthma was significantly reversed, shifting much closer to that of the control group, indicating that SPA has therapeutic effects against asthma. Metabolomic pathway analysis by the ingenuity pathway analysis demonstrated that several pathways including fatty acid metabolism, lipid metabolism, and purine metabolism were significantly altered in asthma. This study offers new methodologies for the understanding of asthma and the mechanisms of SPA in treating asthma.
The impact of Thr91 mutation on c-Src resistance to UM-164: molecular dynamics study revealed a new opportunity for drug design.
Ndagi U, Mhlongo NN, Soliman ME
Mol Biosyst · 2017 May · PMID 28463369 · Publisher ↗
The emergence of a drug resistant non-receptor tyrosine kinase (c-Src) in triple-negative breast cancer (TNBC) remains a prime concern in relation to the burden of TNBC among people living with breast cancer and drug dev...
The emergence of a drug resistant non-receptor tyrosine kinase (c-Src) in triple-negative breast cancer (TNBC) remains a prime concern in relation to the burden of TNBC among people living with breast cancer and drug development. Thr91 mutation was found to induce a complete loss of protein conformation required for drug fitness. Herein, we provide the first account of the molecular impact of the Thr91 mutation on c-Src resistance to experimental drug UM-164 using various computational approaches, namely molecular dynamics simulation, principal component analysis (PCA), dynamic cross-correlation matrices (DCCM) analysis, hydrogen bond occupancy, thermodynamics calculation, ligand-residue interaction and residue interaction networks (RINs). Findings from this study revealed that Thr91 mutation leads to a steric conflict between UM-164 and the side chain of methionine (Met91); this mutation distorts the UM-164 optimum orientation on the conformational space of mutant c-Src compared to the wild-type; decreases hydrogen bond formation between the residues in the mutant protein structure; decreases the UM-164 binding energy in the mutant by -13.416 kcal mol; reduces the residue correlation in the mutant protein structure; induces a change in the overall protein structure conformation from an inactive to active conformation; and distorts the ligand atomic interaction network and the residue interaction network. This report provides important insights that will assist in the further design of novel dual kinase inhibitors to minimise the chances of drug resistance in triple negative breast cancer.
Effect of nucleobase change on cytosine deamination through DNA photo-cross-linking reaction via 3-cyanovinylcarbazole nucleoside.
Sethi S, Ooe M, Sakamoto T … +1 more , Fujimoto K
Mol Biosyst · 2017 Jun · PMID 28453010 · Publisher ↗
Photo-chemical deamination of cytosine using 3-cyanovinylcarbazole nucleoside (K) mediated photo-cross-linking is a technique for site-directed mutagenesis. Using this technique in vivo requires the elimination of a high...
Photo-chemical deamination of cytosine using 3-cyanovinylcarbazole nucleoside (K) mediated photo-cross-linking is a technique for site-directed mutagenesis. Using this technique in vivo requires the elimination of a high-temperature incubation step; instead, incubation should be carried out under physiological conditions. To improve the reactivity of K mediated photo-cross-link induced deamination of cytosine under physiological conditions, an evaluation of base pairing in cytosine was carried out with respect to its deamination. Guanine was replaced with 4 different counter bases (inosine, 2-aminopurine, 5-nitroindole, and nebularine), showing distinct hydrogen bonding patterns with target cytosine, which was incorporated at the -1 position with respect to K in the K-modified photo-responsive oligodeoxyribonucleotides to ascertain the role of hydrogen bonding in deamination under physiological conditions. Among the counter bases, inosine showed the highest acceleration towards the photo-induced deamination reaction.
The characteristic landscape of lncRNAs classified by RBP-lncRNA interactions across 10 cancers.
Zhang Q, Wei Y, Yan Z … +5 more , Wu C, Chang Z, Zhu Y, Li K, Xu Y
Mol Biosyst · 2017 Jun · PMID 28443890 · Publisher ↗
RNA-binding proteins (RBPs) are key regulators of gene expression. Some long non-coding RNAs (lncRNAs) affect gene expression by interacting with RBPs. However, whether this influences the biological characteristics of l...
RNA-binding proteins (RBPs) are key regulators of gene expression. Some long non-coding RNAs (lncRNAs) affect gene expression by interacting with RBPs. However, whether this influences the biological characteristics of lncRNAs in diseases still remains unknown. Here, we classify lncRNAs into two categories, using the interaction information between lncRNAs and RBPs: the lncRNAs that interact with RBPs (Rlncs) and the lncRNAs that do not interact with RBPs (NRlncs). Then we systematically analyze the basic attributes and functions of the two categories of lncRNAs across 10 cancers. By comparing the two categories, we find that the attributes of Rlncs are significantly higher than those of NRlncs in different aspects such as expression level, protein-coding potential, and evolutionary conservation. Furthermore, functional enrichment analysis reveals that the two categories of lncRNAs are involved in different functions and biological pathways. Finally, the prognostic analysis results suggest that the two categories of lncRNAs affect the overall survival of patients through participating in different functions. Our systematic characterization of Rlncs and NRlncs provides a new perspective for understanding the role of lncRNAs, and improves knowledge of cancer biology.
Molecular dynamics investigations of membrane-bound CYP2C19 polymorphisms reveal distinct mechanisms for peripheral variants by long-range effects on the enzymatic activity.
Cui YL, Wu RL
Mol Biosyst · 2017 Jun · PMID 28440827 · Publisher ↗
Increasing sophistication in methods used to account for human polymorphisms in susceptibility to drug metabolism has been one of the success stories in the prevention of adverse drug reactions. Genetic polymorphisms in...
Increasing sophistication in methods used to account for human polymorphisms in susceptibility to drug metabolism has been one of the success stories in the prevention of adverse drug reactions. Genetic polymorphisms in drug-metabolizing enzymes can affect enzyme activity and cause differences in treatment response or drug toxicity. CYP2C19 is one of the most highly polymorphic CYP enzymes and acts on 10-15% of drugs in current clinical use. Despite the number of experimental analyses carried out for this system, the detailed structural basis for altered catalytic properties of polymorphic CYP2C19 variants remains unexplained at the atomic level. To this end, we have investigated the mutation effects on structural characteristics and tunnel geometry upon single point mutations to elucidate the underlying molecular mechanism for the enzymatic activity deficiencies by using the fully atomistic molecular dynamics (MD) simulations in their native, membrane-bound cellular environment. The obtained results demonstrate how significant sequence divergence causes heterogeneous variations, and further affects the shape and chemical properties of the substrate binding site. Principal component analysis (PCA) results combined with free energy calculations have revealed distinct mechanisms for different peripheral variants, implying a more complicated process for the decrease/loss of enzymatic activity upon the introduction of point mutations in CYP2C19 rather than simply structural changes of the region where the mutation is located. Overall, our present study provides important insights into the current pharmacogenetic knowledge of human drug-metabolizing CYP2C19 to understand the large inter-individual variability in drug clearance. The knowledge of heterogeneous variations in structural features could guide future experimental and computational work on efficient and safe drug treatment with better pharmacokinetic properties based on the common variant alleles of CYP genes, which varies among different ethnic populations.
A metabolomic study on high-risk stroke patients determines low levels of serum lysine metabolites: a retrospective cohort study.
Lee Y, Khan A, Hong S … +2 more , Jee SH, Park YH
Mol Biosyst · 2017 May · PMID 28429027 · Publisher ↗
Identifying changes in serum metabolites during cerebral ischemia is an important approach for early diagnosis of thrombotic stroke. Herein, we highlight novel biomarkers for early diagnosis of patients at high risk of t...
Identifying changes in serum metabolites during cerebral ischemia is an important approach for early diagnosis of thrombotic stroke. Herein, we highlight novel biomarkers for early diagnosis of patients at high risk of thrombotic stroke using high resolution metabolomics (HRM). In this retrospective cohort study, serum samples obtained from patients at risk of thrombotic stroke (n = 62) and non-risk individuals (n = 348) were tested using HRM, coupled with LC-MS/MS, to discriminate between metabolic profiles of control and stroke risk patients. Multivariate analysis and orthogonal partial least square-discriminant analysis (OPLS-DA) were performed to determine the top 5% metabolites within 95% group identities, followed by filtering with p-value <0.05 and annotating significant metabolites using a Metlin database. Mapping identified features from Kyoto Encyclopedia of Genes and Genomes (KEGG) and Mummichog resulted in 341 significant features based on OPLS-DA with p-value <0.05. Among these 341 features, nine discriminated the thrombotic stroke risk group from the control group: low levels of N-acetyl-l-lysine, 5-aminopentanoate, cadaverine, 2-oxoglutarate, nicotinamide, l-valine, S-(2-methylpropionyl)-dihydrolipoamide-E and ubiquinone, and elevated levels of homocysteine sulfinic acid. Further analysis showed that these metabolite biomarkers are specifically related to stroke occurrence, and unrelated to other factors such as diabetes or smoking. Lower levels of lysine catabolites in thrombotic stroke risk patients, as compared to the control, supports targeting these compounds as novel biomarkers for early and non-invasive detection of a thrombotic stroke.
Anticancer effects of novel resveratrol analogues on human ovarian cancer cells.
Vergara D, De Domenico S, Tinelli A … +10 more , Stanca E, Del Mercato LL, Giudetti AM, Simeone P, Guazzelli N, Lessi M, Manzini C, Santino A, Bellina F, Maffia M
Mol Biosyst · 2017 May · PMID 28429008 · Publisher ↗
Resveratrol, a naturally occurring phytoalexin, has long been known to play an important regulatory role in key functions in cell physiology. This multifunctional role of resveratrol is explained by its ability to intera...
Resveratrol, a naturally occurring phytoalexin, has long been known to play an important regulatory role in key functions in cell physiology. This multifunctional role of resveratrol is explained by its ability to interact with several targets of various cell pathways. In the recent past, synthetic chemical modifications have been made in an attempt to enhance the biological effects of resveratrol, including its anti-cancer properties. In this study, we investigated the molecular mechanisms of action of novel trans-restricted analogues of resveratrol in which the C-C double bond of the natural derivative has been replaced by diaryl-substituted imidazole analogues. In ovarian cancer models, the results of in vitro screening revealed that the resveratrol analogues exhibited enhanced anti-proliferative properties compared with resveratrol. We found that the resveratrol analogues also significantly inhibited Akt and MAPK signalling and reduced the migration of IL-6 and EGF-treated cells. Finally, in ascite-derived cancer cells, we demonstrated that the resveratrol analogues reduced the expression of epithelial mesenchymal transition (EMT) markers. Collectively, these findings indicate the enhanced anti-cancer properties of the resveratrol analogues.
Generation and characterization of the blood transcriptome of Macaca thibetana and comparative analysis with M. mulatta.
Li P, Du L, Li W … +9 more , Fan Z, Zeng D, Chen H, Zhou L, Yi Y, Yang N, Dou K, Yue B, Li J
Mol Biosyst · 2017 May · PMID 28428989 · Publisher ↗
Transcriptome profiles provide a large transcript sequence data set for genomic study, particularly in organisms that have no accurate genome data published. The Tibetan macaque (Macaca thibetana) is commonly considered...
Transcriptome profiles provide a large transcript sequence data set for genomic study, particularly in organisms that have no accurate genome data published. The Tibetan macaque (Macaca thibetana) is commonly considered to be an endemic species to China and an important animal in biomedical research in the present day. In the present study, we report the de novo assembly and characterization of the blood transcriptome of the Tibetan macaque from three individuals, and we also sequenced the blood transcriptome of the rhesus macaque (Macaca mulatta) for comparison. Using RNA-seq technology, 138 million sequencing reads of the M. thibetana transcriptome were generated. The assembly included 327 871 transcripts with an N50 of 1571 bp. According to the sequence similarity search, 80 317 (24.5%) transcripts were annotated in the nr protein database. All transcripts from M. thibetana and M. mulatta were functionally classified and compared using GO and KEGG analyses. The two transcriptomes were different in the GO term of nutrient reservoir activity, and in the KEGG subcategories of signaling molecules and interaction, infectious diseases, cell growth and death, and immune system. The transcriptomes in this study would provide a valuable resource for future functional and comparative genomic studies, and even for biological studies of this non-human primate.
Microarray profiling and co-expression network analysis of the lncRNAs and mRNAs associated with acute leukemia in adults.
Cheng H, Huang CM, Wang Y … +6 more , Hu XX, Xu XQ, Song XM, Tang GS, Chen L, Yang JM
Mol Biosyst · 2017 May · PMID 28428987 · Publisher ↗
Acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) are common types of acute leukemia in adults and cause low survival rate and poor outcome after 5 years despite high rates of complete remission (CR) wi...
Acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) are common types of acute leukemia in adults and cause low survival rate and poor outcome after 5 years despite high rates of complete remission (CR) with modern chemotherapeutic regimens. To understand the distinct mechanisms in leukemogenesis for ALL and AML and to identify markers for diagnosis and treatment, lncRNA and mRNA expression profiles of AML and ALL patients and healthy controls were generated using microarray analysis. For comparison, the differentially expressed mRNA functions were annotated using gene ontology (GO) and pathway analysis. The microarray revealed that 1011 lncRNAs and 2656 mRNAs differed in AML patients and 6069 lncRNAs and 5338 mRNAs differed in ALL patients from those in healthy controls. The GO terms and KEGG pathway annotation data revealed that the olfactory receptor activity, G-protein coupled receptor activity and olfactory transduction-related genes were significantly associated with AML and ALL. Co-expression network analysis indicated that 108 lncRNAs and 85 mRNAs were included in the co-expression network. This study is the first to explore genome-wide lncRNA expression and co-expression with mRNA patterns in AML and ALL using microarray technology and could provide basic information for new biomarkers or treatment targets to alleviate AML and ALL.
Antibodies to H2a and H2b histones from the sera of HIV-infected patients catalyze site-specific degradation of these histones.
Baranova SV, Dmitrienok PS, Ivanisenko NV … +2 more , Buneva VN, Nevinsky GA
Mol Biosyst · 2017 Jun · PMID 28426042 · Publisher ↗
Histones and their post-translational modifications have key roles in chromatin remodeling and gene transcription. Besides intranuclear functions, histones act as damage-associated molecules when they are released into t...
Histones and their post-translational modifications have key roles in chromatin remodeling and gene transcription. Besides intranuclear functions, histones act as damage-associated molecules when they are released into the extracellular space. Administration of histones to animals leads to systemic inflammatory and toxic responses. Autoantibodies with enzymatic activities (abzymes) are distinctive features of some autoimmune and viral diseases. Electrophoretically homogeneous IgGs containing no canonical enzymes were isolated from the sera of HIV-infected patients by chromatography on several affinity sorbents including anti-histone Sepharose. In contrast to canonical proteases (trypsin, chymotrypsin, proteinase K), IgGs from HIV-infected patients specifically hydrolyzed only histones but not many other tested globular proteins. Using MALDI mass spectrometry the sites of H2a and H2b histone cleavage by anti-histone IgGs were determined for the first time. One cluster of H2a hydrolysis contains two major (↕) and four moderate (↓) cleavage sites: 31-H↓R↓L↓L↓R↕K G↕N-38. One major and two moderate sites of cleavage were revealed in the second cluster: 14-A↕KSRS↓SRA↓G-22. The third cluster corresponding to the H2a C-terminal part contains only five minor (†) sites of cleavage: 82-H†LQLAIRNDEELN†KLLG†RV†T†I-102. It was shown that two major and four moderate sites of cleavage were present in the main cluster of H2b hydrolysis: 46-K↕QvhpD↓TgiS↓SkA↓M↕GiM↓N-63. Two moderate sites of cleavage correspond to a relatively short 6-mer cluster: 12-K↓GskK↓A-17. The third relatively long 9-mer cluster contains one major and two minor sites of H2b cleavage: 80-L↕AHYN†KRS†T-88. In the nucleosome core particle, most of the major and moderate cleavage sites are located at the H2a/H2b interaction interface. Minor cleavage sites of H2a are involved in binding with H3 in the nucleosome core. Two moderate cleavage sites of H2b and one major cleavage site of H2a are located in the disordered N-terminal region interacting with DNA. According to the crystal structure of the nucleosome core particle, all identified cleavage sites are expected to affect H2a and H2b folding, nucleosome assembly, and binding of H2a and H2b with DNA. The existence of H2a and H2b hydrolyzing abzymes may be very important for the further understanding of unknown possibilities of immune systems and biological functions of antibodies.
An integrated anti-arrhythmic target network of compound Chinese medicine Wenxin Keli revealed by combined machine learning and molecular pathway analysis [corrected].
Wang T, Lu M, Du Q … +7 more , Yao X, Zhang P, Chen X, Xie W, Li Z, Ma Y, Zhu Y
Mol Biosyst · 2017 May · PMID 28418441 · Publisher ↗
Wenxin Keli (WK), a Chinese patent medicine, is known to be effective against cardiac arrhythmias and heart failure. Although a number of electrophysiological findings regarding its therapeutic effect have been reported,...
Wenxin Keli (WK), a Chinese patent medicine, is known to be effective against cardiac arrhythmias and heart failure. Although a number of electrophysiological findings regarding its therapeutic effect have been reported, the active components and system-level characterizations of the component-target interactions of WK have yet to be elucidated. In the current study, we present the first report of a new protective effect of WK on suppressing anti-arrhythmic-agent-induced arrhythmias. In a model of isolated guinea pig hearts, rapid perfusion of quinidine altered the heart rate and prolonged the Q-T interval. Pretreatment with WK significantly prevented quinidine-induced arrhythmias. To explain the therapeutic and protective effects of WK, we constructed an integrated multi-target pharmacological mechanism prediction workflow in combination with machine learning and molecular pathway analysis. This workflow had the ability to predict and rank the probability of each compound interacting with 1715 target proteins simultaneously. The ROC value statistics showed that 97.786% of the values for target prediction were larger than 0.8. We applied this model to carry out target prediction and network analysis for the identified components of 5 herbs in WK. Using the 124 potential anti-arrhythmic components and the 30 corresponding protein targets obtained, an integrative anti-arrhythmic molecular mechanism of WK was proposed. Emerging drug/target networks suggested ion channel and intracellular calcium and autonomic nervous and hormonal regulation had critical roles in WK-mediated anti-arrhythmic activity. A validation of the proposed mechanisms was achieved by demonstrating that calaxin, one of the WK components from Gansong, dose-dependently blocked its predicted target Ca1.2 channel in an electrophysiological assay.
An all-atom molecular dynamics study of the anti-interferon signaling of Ebola virus: interaction mechanisms of EBOV VP24 binding to Karyopherin alpha5.
Ding JN, Zhang YJ, Zhong H … +3 more , Ao CC, Li J, Han JG
Mol Biosyst · 2017 May · PMID 28418440 · Publisher ↗
Ebola virus (EBOV) is highly lethal due to virally encoded immune antagonists, and the combination of EBOV VP24 with karyopherin alpha (KPNA) will trigger anti-interferon (IFN) signaling. The crystal structure of VP24-KP...
Ebola virus (EBOV) is highly lethal due to virally encoded immune antagonists, and the combination of EBOV VP24 with karyopherin alpha (KPNA) will trigger anti-interferon (IFN) signaling. The crystal structure of VP24-KPNA5 has been proposed in recent studies, but the precise binding mechanisms are still unclear. In order to explore the VP24-KPNA5 protein binding micro-mechanisms, Molecular Dynamic (MD) simulations and Molecular Mechanics Generalized Born Surface Area (MM-GB/SA) energy calculation are performed. The obtained results show that EBOV VP24 binding to KPNA5 will rigidify their binding-face, and both proteins will be compacted during binding. According to the analyses of binding free energies of WT and the eight mutant systems, MUT3 makes the most effective contributions to the interaction; additionally MUT4, R398A and the double mutant have the second most effective influence. Hydrogen bond analysis demonstrates that inhibitors which can interfere with the formation of hydrogen bonds D480-T138, E483-R137 and D205-R396 will prevent the anti-IFN effect. Meanwhile, by combining the decomposition of binding free energies (DC) with computational alanine scanning (CAS) results, it is shown that VP24 residues R137 and T138 will be potential targets for EBOV VP24 inhibitors, and KPNA5 residues R396, R398, R480, Y477 and F484 will be potential targets to prevent KPNA5 binding to VP24, which will ultimately block anti-IFN signaling. Our investigations provide theoretical data to understand the binding modes of VP24-KPNA5. The precise binding mechanisms of the complex may shed light on the development of potential novel inhibitors against EBOV infection.
A structural bioinformatics investigation on protein-DNA complexes delineates their modes of interaction.
Gardini S, Furini S, Santucci A … +1 more , Niccolai N
Mol Biosyst · 2017 May · PMID 28418051 · Publisher ↗
The lifetimes of protein-DNA adducts are strictly related to the various protein functions. This feature must be encoded by the amino acids located at the protein-DNA interface. The large number of structurally character...
The lifetimes of protein-DNA adducts are strictly related to the various protein functions. This feature must be encoded by the amino acids located at the protein-DNA interface. The large number of structurally characterized protein-DNA complexes now available from the Protein Data Bank (PDB) allows extensive structural bioinformatics investigations on protein-DNA interfaces. The modes of protein binding to DNA have been explored by dividing 629 non-redundant PDB files of protein-DNA complexes into separate classes for structural proteins, transcription factors and DNA-related enzymes. From the selected PDB structures, we could define 2953 protein-DNA contact regions. A systematic analysis of amino acid occurrences at these protein-DNA contact regions yielded composition profiles, which are typical for each of the three protein classes. The critical role of some amino acids to influence intermolecular contact lifetimes is discussed here. The occurrence of arginine at the protein-DNA interface, by far the most abundant amino acid in this protein moiety, is found to be the main feature that differentiates proteins from the three classes. Structural proteins and, to a lesser extent, transcription factors exhibit the highest Arg occurrence at protein-DNA contact regions. Reduced Arg/Lys ratios together with increased contents of Asp and Glu are observed in all the DNA-interacting enzymes. The amount of negatively charged side chains, highly conserved among homologous DNA-related enzymes at protein-DNA interfaces, is suggested as a tool to modulate protein mobility along DNA chains. Arg/Lys, Asp/Asn and Glu/Gln substitutions at protein-DNA interfaces may represent a very feasible way to control protein motion on DNA rails.
Small molecule induced poly(A) single strand to self-structure conformational switching: evidence for the prominent role of H-bonding interactions.
Chatterjee S, Suresh Kumar G
Mol Biosyst · 2017 May · PMID 28405661 · Publisher ↗
All messenger RNAs (mRNAs) have a polyadenylic acid tail that is added during post transcriptional RNA processing. Investigation of the structure-function and interactions of polyadenylic acid is an important area to tar...
All messenger RNAs (mRNAs) have a polyadenylic acid tail that is added during post transcriptional RNA processing. Investigation of the structure-function and interactions of polyadenylic acid is an important area to target for cancer and related diseases. Jatrorrhizine and coptisine are two important isoquinoline alkaloids that are structurally very similar, differing only in the substituents on the isoquinoline chromophore. Here we demonstrate that these alkaloids differentially induce a self-structure in single stranded poly(A) using absorbance, thermal melting and differential scanning calorimetry experiments. Jatrorrhizine was found to be more effective than coptisine in binding to poly(A) from spectroscopy and calorimetry data. Molecular modeling results suggested the involvement of more H-bonds in the complexation of the former with poly(A). It appears that the presence of substituents on the alkaloid that can form H-bonding interactions with the adenine nucleotides may play a critical role in the binding and structural rearrangement of poly(A) into the self-structure. The atomic force microscopy data directly visualized the poly(A) self-structured network. We propose a plausible mechanism of the small molecule induced self-structure formation in poly(A). The results presented here may help in the design of effective poly(A) targeted molecules for therapeutic use.
Integrating multiple omics data for the discovery of potential Beclin-1 interactions in breast cancer.
Chen Y, Wang X, Wang G … +9 more , Li Z, Wang J, Huang L, Qin Z, Yuan X, Cheng Z, Zhang S, Yin Y, He J
Mol Biosyst · 2017 May · PMID 28401970 · Publisher ↗
Breast cancer has been reported as one of the most frequently diagnosed malignant diseases and the leading cause of cancer death in women all around the world. Furthermore, this complicated cancer is divided into multipl...
Breast cancer has been reported as one of the most frequently diagnosed malignant diseases and the leading cause of cancer death in women all around the world. Furthermore, this complicated cancer is divided into multiple subtypes which present different clinical symptoms and need correspondingly directed therapy. We took BECN1, a core gene in autophagy performing a tumor inhibitory effect, as a starting point. The study in this paper aims to identify genes related to breast cancer and its multiple subtypes by integrating multiple omics data using the least absolute shrinkage and selection operator (LASSO), which is a statistical method that can integrate more than two types of omics data. All the data is obtained from The Cancer Genome Atlas (TCGA) platform which stores clinical and molecular tumor data. The model constructed is based on three kinds of data including mRNA-gene expression with a dependent variable level, DNA methylation and copy number alterations as independent variables. Finally, we propose four subnets of four subtypes of breast cancer, and consider as a result of microarray analysis that AFF3 is associated with BECN1 in breast cancer, and may be a potential therapeutic target. This finding may provide some potential targeted therapeutics for the four different subtypes of breast cancer at the genetic level. In conclusion, finding out the major role Beclin-1 plays in breast cancer subtypes is of great value. The results obtained are instructive for further research and may provide excellent results in clinical applications, as well as testing in animal experiments, and may also indicate a new method to perform bioinformatics analysis.
Predicting protein lysine phosphoglycerylation sites by hybridizing many sequence based features.
Chen QY, Tang J, Du PF
Mol Biosyst · 2017 May · PMID 28396891 · Publisher ↗
Post-translational modification (PTM) is essential for many biological processes. Covalent and generally enzymatic modification of proteins can impact the activity of proteins. Modified proteins would have more complex s...
Post-translational modification (PTM) is essential for many biological processes. Covalent and generally enzymatic modification of proteins can impact the activity of proteins. Modified proteins would have more complex structures and functions. Knowing whether a specific residue is modified or not is significant to unravel the function and structure of this protein. As experimental approaches to discover protein PTM sites are always costly and time consuming, computational prediction methods are desirable alternative methods. Lysine phosphoglycerylation is a type of newly discovered PTM that is related to glycolytic process and glucose metabolism. Since the lysine phosphoglycerylation process requires no catalytic enzyme, its site selectivity mechanism is still not fully understood. In this study, we designed a novel computational method, namely PhoglyPred, to identify lysine phosphoglycerylation sites. By utilizing several different protein sequence descriptors, PhoglyPred achieved an overall accuracy of 90.3% in a Jackknife test, which is better than other state-of-the-art predictors. By analyzing the importance of different features using the F-score, we found several important sequence features, which may benefit future studies in understanding the site selectivity mechanism of lysine phosphoglycerylation.
About
- Frequency
- Sun
- Papers found
- 200
- RSS feed
- Subscribe