Current Protein & Peptide Science[JOURNAL]
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168 papers
Native chemical ligation with Nalpha acyl transfer auxiliaries.
Offer J
Biopolymers · 2010 · PMID 20593473 · Publisher ↗
Native chemical ligation (NCL) is a simple procedure that enables synthetic access to many proteins and is increasingly harnessed to study protein structure and function. However, the generality of this method is limited...
Native chemical ligation (NCL) is a simple procedure that enables synthetic access to many proteins and is increasingly harnessed to study protein structure and function. However, the generality of this method is limited by the requirement for cysteine residues suitably positioned throughout the target protein. Auxiliary approaches have been developed to overcome this limitation, wherein a removable group is introduced at the amino terminus of a peptide conveying ligation properties comparable to cysteine. Present auxiliary approaches combine the thioester exchange concept applied first in NCL with a number of acyl transfer reactions first systematically explored by Kemp and coworkers. The current methods for auxiliary mediated ligation appear promising for the synthesis of proteins and in particular post-translational modified proteins.
Endosome-disruptive peptides for improving cytosolic delivery of bioactive macromolecules.
Nakase I, Kobayashi S, Futaki S
Biopolymers · 2010 · PMID 20564044 · Publisher ↗
Along with recent advances in therapeutic technologies based on biomacromolecules, including genes, oligonucleotides, and proteins, the development of technologies for improving the efficiency of the delivery of these th...
Along with recent advances in therapeutic technologies based on biomacromolecules, including genes, oligonucleotides, and proteins, the development of technologies for improving the efficiency of the delivery of these therapeutic molecules into cells, more specifically into the cytosol and nucleus, is significantly required. Cell membranes are major impediments to the delivery of therapeutic macromolecules into cells. These macromolecules are usually taken up by the cells via endocytosis, and their translocation from endosomes to the cytosol is a critical step to determine their therapeutic effects. Many viruses and bacterial toxins use endocytic pathways to invade the host mammalian cells, and some of these pathogens have the ability to facilitate their endosomal escape into the cytosol by pH-induced alteration in their component proteins that leads to the disruption of the endosomal membranes and the eventual membrane fusions. To simulating these functions, endosome-disruptive peptides have been used for the intracellular delivery of biomacromolecules to accelerate their endosomal escape by sensing the endosomal acidification. In this review, current approaches for the intracellular delivery using these endosome-disruptive peptides are surveyed.
Cyclic peptides as potential therapeutic agents for skin disorders.
Namjoshi S, Benson HA
Biopolymers · 2010 · PMID 20564043 · Publisher ↗
There is an increasing understanding of the role of peptides in normal skin function and skin disease. With this knowledge, there is significant interest in the application of peptides as therapeutics in skin disease or...
There is an increasing understanding of the role of peptides in normal skin function and skin disease. With this knowledge, there is significant interest in the application of peptides as therapeutics in skin disease or as cosmeceuticals to enhance skin appearance. In particular, antimicrobial peptides and those involved in inflammatory processes provide options for the development of new therapeutic directions in chronic skin conditions such as psoriasis and dermatitis. To exploit their potential, it is essential that these peptides are delivered to their site of action in active form and in sufficient quantity to provide the desired effect. Many polymers permeate the skin poorly and are vulnerable to enzymatic degradation. Synthesis of cyclic peptide derivatives can substantially alter the physicochemical characteristics of the peptide with the potential to improve its skin permeation. In addition, cyclization can stabilize the peptide structure and thereby increase its stability. This review describes the role of cyclic peptides in the skin, examples of current cyclic peptide therapeutic products, and the potential for cyclic peptides as dermatological therapeutics and cosmeceuticals.
Cyclotide synthesis and supply: from plant to bioprocess.
Dörnenburg H
Biopolymers · 2010 · PMID 20564040 · Publisher ↗
Cyclotides are disulfide-rich miniproteins with a circular backbone and a knotted arrangement ofdisulfide bonds. Because these plant-derived peptides are resistant to degradation and exhibit a diverse range of bioactivit...
Cyclotides are disulfide-rich miniproteins with a circular backbone and a knotted arrangement ofdisulfide bonds. Because these plant-derived peptides are resistant to degradation and exhibit a diverse range of bioactivity they have become important agronomic and industrial objectives. They belong to a group of compounds with low market volume and high price that are poorly processed by microorganisms, are too complex for economic chemical synthesis, and thus are valuable candidates for the synthesis in plant cell bioprocesses. This review highlights current research aimed at production routes of cyclotides in Oldenlandia affinis plantlets and cell cultures, and summarizes recent advances in bioprocessing aspects, with particular emphasis on the development of suitable bioreactor configurations for plant cell culture-based processes, the optimization of culture environments as a powerful means to improve yields, bioreactor operational modes, and trends in protein recovery.
Building a bridge between peptide chemistry and organic chemistry: intramolecular macrocyclization reactions and supramolecular chemistry with helical peptide substrates.
Moretto A, Crisma M, Formaggio F … +1 more , Toniolo C
Biopolymers · 2010 · PMID 20564031 · Publisher ↗
In our ongoing efforts to build a bridge between peptide chemistry and organic chemistry, we are currently investigating: (1) two types of intramolecular macrocyclization reactions in 3(10)-helical peptides, and (2) a pe...
In our ongoing efforts to build a bridge between peptide chemistry and organic chemistry, we are currently investigating: (1) two types of intramolecular macrocyclization reactions in 3(10)-helical peptides, and (2) a peptido[2]rotaxane molecular machine as a supramolecular tool using a 3(10)-helical peptide as the axle. More specifically, we studied the following two reactions: (a) the intramolecular ring-closing olefin metathesis between two amino acid residues with side chains bearing an allyl group, and (b) the intramolecular Paternò-Yang photoreaction, using a benzophenone-based amino acid as a photoaffinity reagent for a Met residue. Both reactions involve formation of a new C--C bond. As for the supramolecular system examined, we were able to identify the two stations of a new peptido[2]rotaxane characterized by an -(Aib)(6)- axle and to reversibly switch the aromatic tetramide macrocyclic wheel from one station to the next. This article summarizes the information available in the literature from other groups and the published/unpublished data originated from our laboratory on these research areas.
Cyclotides, a promising molecular scaffold for peptide-based therapeutics.
Jagadish K, Camarero JA
Biopolymers · 2010 · PMID 20564025 · Full text
Cyclotides are a new emerging family of large plant-derived backbone-cyclized polypeptides (approximately 30 amino acids long) that share a disulfide-stabilized core (three disulfide bonds) characterized by an unusual kn...
Cyclotides are a new emerging family of large plant-derived backbone-cyclized polypeptides (approximately 30 amino acids long) that share a disulfide-stabilized core (three disulfide bonds) characterized by an unusual knotted structure. Their unique circular backbone topology and knotted arrangement of three disulfide bonds make them exceptionally stable to thermal, chemical, and enzymatic degradation compared to other peptides of similar size. Currently, more than 100 sequences of different cyclotides have been characterized, and the number is expected to increase dramatically in the coming years. Considering their stability and biological activities like anti-HIV, uterotonic, and insecticidal, and also their abilities to cross the cell membrane, cyclotides can be exploited to develop new stable peptide-based drugs. We have recently demonstrated the intriguing possibility of producing libraries of cyclotides inside living bacterial cells. This opens the possibility to generate large genetically encoded libraries of cyclotides that can then be screened inside the cell for selecting particular biological activities in a high-throughput fashion. The present minireview reports the efforts carried out toward the selection of cyclotide-based compounds with specific biological activities for drug design.
Analysis and classification of circular proteins in CyBase.
Kaas Q, Craik DJ
Biopolymers · 2010 · PMID 20564021 · Publisher ↗
CyBase is a database dedicated to the study of the sequences and three-dimensional structures of ribosomally synthesized, backbone cyclized proteins, and their synthetic variants. This article describes CyBase data and t...
CyBase is a database dedicated to the study of the sequences and three-dimensional structures of ribosomally synthesized, backbone cyclized proteins, and their synthetic variants. This article describes CyBase data and tools that are useful in the analysis of circular proteins. Circular proteins have now been discovered in organisms from all kingdoms of life, and given the current rate of discovery they could soon number in the thousands. Presently CyBase manages 427 protein sequences, 106 nucleic acid sequences, and 49 protein three-dimensional structures from 44 different species. Circular proteins are grouped into distinct classes according to their origin and sequence similarities. These classes include trypsin inhibitors, bacterial proteins, mushroom toxins, cyclotides, and cyclic defensins from primates. Several protein classification types are used in CyBase to designate proteins extracted from natural resources (wild type and precursor) or engineered (modified wild type, grafted, mutant, cyclic permutant, and acyclic permutant). CyBase has tools for the analysis of mass spectrum fingerprints of cyclic peptides, and assists in the discovery of new circular proteins. Some of the developments detailed here have been made specifically for the largest class of circular proteins, the cyclotides, but could be adapted for other classes of cyclic proteins. The cyclotide-specific tools include two-dimensional representations of domains and alternative displays of alignments for precursor sequences. This alignment prompted us to propose a revision of the cydclotide precursor organization, in which the repeated regions now include a small C-terminal region, which appears to have a significant role in the biosynthesis of mature cyclotides.
Fiber formation of a synthetic spider peptide derived from Nephila clavata.
Hidaka Y, Kontani K, Taniguchi R … +5 more , Saiki M, Yokoi S, Yukuhiro K, Yamaguchi H, Miyazawa M
Biopolymers · 2011 · PMID 20564008 · Publisher ↗
Dragline silk is a high-performance biopolymer with exceptional mechanical properties. Artificial spider dragline silk is currently prepared by a recombinant technique or chemical synthesis. However, the recombinant proc...
Dragline silk is a high-performance biopolymer with exceptional mechanical properties. Artificial spider dragline silk is currently prepared by a recombinant technique or chemical synthesis. However, the recombinant process is costly and large-sized synthetic peptides are needed for fiber formation. In addition, the silk fibers that are produced are much weaker than a fiber derived from a native spider. In this study, a small peptide was chemically synthesized and examined for its ability to participate in fiber formation. A short synthetic peptide derived from Nephila clavata was prepared by a solid-phase peptide method, based on a prediction using the hydrophobic parameter of each individual amino acid residue. After purification of the spider peptide, fiber formation was examined under several conditions. Fiber formation proceeded in the acidic pH range, and larger fibers were produced when organic solvents such as trifluoroethanol and acetonitrile were used at an acidic pH. Circular dichroism measurements of the spider peptide indicate that the peptide has a beta-sheet structure and that the formation of a beta-sheet structure is required for the spider peptide to undergo fiber formation.
A new "era" for cyclotide sequencing.
Colgrave ML, Poth AG, Kaas Q … +1 more , Craik DJ
Biopolymers · 2010 · PMID 20564007 · Publisher ↗
In recent years, the discovery of a large family of macrocyclic peptides, the cyclotides, has revealed Natures ingenuity in molecular drug design. The incorporation of a cyclic peptide backbone and a knotted arrangement...
In recent years, the discovery of a large family of macrocyclic peptides, the cyclotides, has revealed Natures ingenuity in molecular drug design. The incorporation of a cyclic peptide backbone and a knotted arrangement of disulfide bridges into their structures confers extraordinary chemical, thermal, and enzymatic stability on these biologically active peptides. However, these structural attributes present challenges in the identification of cyclotides. Until now, the sequencing of cyclotides has been slow and inefficient owing to inherent difficulties in the separation of these hydrophobic peptides from plants, the multiple chemical and enzymatic derivatization steps required to make them amenable to mass spectrometric sequencing, and the lack of software tools to efficiently deal with these circular permutants. The current bottleneck slowing the speed of cyclotide sequencing is the requirement for multiple HPLC purification steps before analysis. Here, we have applied proteomic strategies to fast-track the discovery of known, modified and novel sequences. Using four fractions from a previously well-characterized cyclotide-containing plant species, Viola odorata, 11 new sequences, as well as a plethora of known and modified cyclotides, were uncovered. In addition, the methodology was validated through analysis of crude leaf extracts ofOldenlandia affinis and Arabidopsis thaliana. The unambiguous identification of a suite of cyclotides in the Oldenlandia affinis extract provided the ultimate proof-of-concept for this application. Major advances in methodology include the use of optimized LC-MS/MS conditions and design of a custom-built cyclotide database, in which mature cyclotide sequences are excised, replicated and appended, marking a new "era" for cyclotide sequencing.
Fibrillar peptide gels in biotechnology and biomedicine.
Jung JP, Gasiorowski JZ, Collier JH
Biopolymers · 2010 · PMID 20091870 · Full text
Peptides, peptidomimetics, and peptide derivatives that self-assemble into fibrillar gels have received increasing interest as synthetic extracellular matrices for applications in 3D cell culture and regenerative medicin...
Peptides, peptidomimetics, and peptide derivatives that self-assemble into fibrillar gels have received increasing interest as synthetic extracellular matrices for applications in 3D cell culture and regenerative medicine. Recently, several of these fibrillizing molecules have been functionalized with bioactive components and chemical features such as cell-binding ligands, degradable sequences, drug eluting compounds, and cross-linkable groups, thereby producing gels that can reliably display multiple factors simultaneously. This capacity for incorporating precise levels of many different biological and chemical factors is advantageous given the natural complexity of cell-matrix interactions that many current biomaterial strategies seek to mimic. In this review, recent efforts in the area of fibril-forming peptide materials are described, and advantages of biomaterials containing multiple modular elements are outlined. In addition, a few hurdles and open questions surrounding fibrillar peptide gels are discussed, including issues of the materials' structural heterogeneity, challenges in fully characterizing the diversity of their self-assembled structures, and incomplete knowledge of how the materials are processed in vivo.
Real-time detection of single-living pancreatic beta-cell by laser tweezers Raman spectroscopy: high glucose stimulation.
Rong X, Huang SS, Kuang XC … +1 more , Liu H
Biopolymers · 2010 Jul · PMID 20091674 · Publisher ↗
Glucose acts as a beta-cell stimulus factor and leads to cellular responses that involve a large amount of biomolecule formation, relocation, and transformation. We hypothesize that information about these changes can be...
Glucose acts as a beta-cell stimulus factor and leads to cellular responses that involve a large amount of biomolecule formation, relocation, and transformation. We hypothesize that information about these changes can be obtained in real-time by laser tweezers Raman spectroscopy. To test this hypothesis, repeated measurements designs in accordance with the application of Raman spectroscopy detection were used in the current experiment. Single rat beta-cells were measured by Raman spectroscopy in 2.8 mmol/l glucose culture medium as a basal condition. After stimulation with high glucose (20 mmol/l), the same cells were measured continuously. Each cell was monitored over a total time span of 25 min, in 5 min intervals. During this period of time, cells were maintained at an appropriate temperature controlled by an automatic heater, to provide near-physiological conditions. It was found that some significant spectral changes induced by glucose were taking place during the stimulation time course. The most noticeable changes were the increase of spectral intensity at the 1002, 1085, 1445, and 1655 cm(-1) peaks, mainly corresponding to protein and lipid. We speculate that these changes might have to do with beta-cell protein and lipid synthesis. Using laser tweezers Raman spectroscopy in combination with glucose stimulation, optical spectral information from rat beta-cells was received and analyzed.
A proposed model for dragline spider silk self-assembly: insights from the effect of the repetitive domain size on fiber properties.
Ittah S, Barak N, Gat U
Biopolymers · 2010 May · PMID 20014164 · Publisher ↗
Dragline spider silk has been intensively studied for its superior qualities as a biomaterial. In previous studies, we made use of the baculovirus mediated expression system for the production of a recombinant Araneus di...
Dragline spider silk has been intensively studied for its superior qualities as a biomaterial. In previous studies, we made use of the baculovirus mediated expression system for the production of a recombinant Araneus diadematus spider silk dragline ADF4 protein and its self-assembly into intricate fibers in host insect cells. In this study, our aim was to explore the function of the major repetitive domain of the dragline spider silk. Thus, we generated an array of synthetic proteins, each containing a different number of identical repeats up to the largest recombinantly expressed spider silk to date. Study of the self-assembly properties of these proteins showed that depending on the increasing number of repeats they give rise to different assembly phenotypes, from a fully soluble protein to bona fide fibers with superior qualities. The different assembly forms, the corresponding chemical resistance properties obtained as well as ultrastructural studies, revealed novel insights concerning the structure and intermolecular interactions of the repetitive and nonrepetitive domains. Based on these observations and current knowledge in the field, we hereby present a comprehensive hypothetical model for the mechanism of dragline silk self-assembly and fiber formation.
Analysis of a new crystal form of procarboxypeptidase B: further insights into the catalytic mechanism.
Fernández D, Boix E, Pallarès I … +2 more , Avilés FX, Vendrell J
Biopolymers · 2010 Feb · PMID 19802820 · Publisher ↗
A new triclinic crystal structure form of porcine pancreatic procarboxypeptidase B (PCPB) was obtained at higher resolution than the previously known tetragonal crystal structure. This new crystal polymorph has allowed f...
A new triclinic crystal structure form of porcine pancreatic procarboxypeptidase B (PCPB) was obtained at higher resolution than the previously known tetragonal crystal structure. This new crystal polymorph has allowed for a corrected, accurate assignment of residues along the polypeptide chain based on the currently available gene sequence information and crystallographic data. The present structure shows unbound PCPB in a distinct molecular packing as compared to the previous benzamidine complexed form. Its catalytically important Tyr248 residue is oriented and hydrogen-bonded to solvent water molecules, and locates the furthest away from the catalytic zinc ion as compared to previous structures. A relatively long stretch of residues flanking Tyr248 and guarding the access to the catalytic zinc ion was found to be sequentially unique to the M14 family of peptidases. Predictions from a normal mode analysis indicated that this stretch of residues belongs to a rigid subdomain in the protein structure. The specific presence of a tyrosyl residue at the most exposed position in this region would allow for a delicate balance between extreme hydrophobicity and hydrophilicity, and affect substrate binding and the kinetic efficiency of the enzyme.
Hsp70 molecular chaperones and Parkinson's disease.
Witt SN
Biopolymers · 2010 Mar · PMID 19768775 · Publisher ↗
Because over expression of Hsp70 molecular chaperones suppresses the toxicity of aberrantly folded proteins that occur in Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis, and various pol...
Because over expression of Hsp70 molecular chaperones suppresses the toxicity of aberrantly folded proteins that occur in Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis, and various polyQ-diseases (Huntington's disease and ataxias), Hsp70 is garnering attention as a possible therapeutic agent for these various diseases. Here, I review progress in this fascinating field of molecular chaperones and neurodegeneration and describe our current understanding of the mechanisms by which Hsp70 protects cells from the PD-related protein called alpha-synuclein (alpha-syn).
Structure and function of the molecular chaperone Hsp104 from yeast.
Grimminger-Marquardt V, Lashuel HA
Biopolymers · 2010 Mar · PMID 19768774 · Publisher ↗
The molecular chaperone Hsp104 plays a central role in the clearance of aggregates after heat shock and the propagation of yeast prions. Hsp104's disaggregation activity and prion propagation have been linked to its abil...
The molecular chaperone Hsp104 plays a central role in the clearance of aggregates after heat shock and the propagation of yeast prions. Hsp104's disaggregation activity and prion propagation have been linked to its ability to resolubilize or remodel protein aggregates. However, Hsp104 has also the capacity to catalyze protein aggregation of some substrates at specific conditions. Hence, it is a molecular chaperone with two opposing activities with respect to protein aggregation. In yeast models of Huntington's disease, Hsp104 is required for the aggregation and toxicity of polyglutamine (polyQ), but the expression of Hsp104 in cellular and animal models of Huntington's and Parkinson's disease protects against polyQ and alpha-synuclein toxicity. Therefore, elucidating the molecular determinants and mechanisms underlying the ability of Hsp104 to switch between these two activities is of critical importance for understanding its function and could provide insight into novel strategies aimed at preventing or reversing the formation of toxic protein aggregation in systemic and neurodegenerative protein misfolding diseases. Here, we present an overview of the current molecular models and hypotheses that have been proposed to explain the role of Hsp104 in modulating protein aggregation and prion propagation. The experimental approaches and the evidences presented so far in relation to these models are examined. Our primary objective is to offer a critical review that will inspire the use of novel techniques and the design of new experiments to proceed towards a qualitative and quantitative understanding of the molecular mechanisms underlying the multifunctional properties of Hsp104 in vivo.
Peptidic modulators of protein-protein interactions: progress and challenges in computational design.
Rubinstein M, Niv MY
Biopolymers · 2009 Jul · PMID 19226619 · Publisher ↗
With the decline in productivity of drug-development efforts, novel approaches to rational drug design are being introduced and developed. Naturally occurring and synthetic peptides are emerging as novel promising compou...
With the decline in productivity of drug-development efforts, novel approaches to rational drug design are being introduced and developed. Naturally occurring and synthetic peptides are emerging as novel promising compounds that can specifically and efficiently modulate signaling pathways in vitro and in vivo. We describe sequence-based approaches that use peptides to mimic proteins in order to inhibit the interaction of the mimicked protein with its partners. We then discuss a structure-based approach, in which protein-peptide complex structures are used to rationally design and optimize peptidic inhibitors. We survey flexible peptide docking techniques and discuss current challenges and future directions in the rational design of peptidic inhibitors.
Understanding the mechanism of beta-sheet folding from a chemical and biological perspective.
Jager M, Deechongkit S, Koepf EK … +5 more , Nguyen H, Gao J, Powers ET, Gruebele M, Kelly JW
Biopolymers · 2008 · PMID 18844292 · Publisher ↗
Perturbing the structure of the Pin1 WW domain, a 34-residue protein comprised of three beta-strands and two intervening loops has provided significant insight into the structural and energetic basis of beta-sheet foldin...
Perturbing the structure of the Pin1 WW domain, a 34-residue protein comprised of three beta-strands and two intervening loops has provided significant insight into the structural and energetic basis of beta-sheet folding. We will review our current perspective on how structure acquisition is influenced by the sequence, which determines local conformational propensities and mediates the hydrophobic effect, hydrogen bonding, and analogous intramolecular interactions. We have utilized both traditional site-directed mutagenesis and backbone mutagenesis approaches to alter the primary structure of this beta-sheet protein. Traditional site-directed mutagenesis experiments are excellent for altering side-chain structure, whereas amide-to-ester backbone mutagenesis experiments modify backbone-backbone hydrogen bonding capacity. The transition state structure associated with the folding of the Pin1 WW domain features a partially H-bonded, near-native reverse turn secondary structure in loop 1 that has little influence on thermodynamic stability. The thermodynamic stability of the Pin1 WW domain is largely determined by the formation of a small hydrophobic core and by the formation of desolvated backbone-backbone H-bonds enveloped by this hydrophobic core. Loop 1 engineering to the consensus five-residue beta-bulge-turn found in most WW domains or a four-residue beta-turn found in most beta-hairpins accelerates folding substantially relative to the six-residue turn found in the wild type Pin1 WW domain. Furthermore, the more efficient five- and four-residue reverse turns now contribute to the stability of the three-stranded beta-sheet. These insights have allowed the design of Pin1 WW domains that fold at rates that approach the theoretical speed limit of folding.
The intracellular and nuclear-targeted delivery of an antiandrogen drug by carrier peptides.
Hodoniczky J, Sims CG, Best WM … +2 more , Bentel JM, Wilce JA
Biopolymers · 2008 · PMID 18351583 · Publisher ↗
Cell permeable carrier peptides are currently of interest for their potential to improve the delivery of bioactive molecules into cells and to specific cellular compartments. We have investigated the activity of a deriva...
Cell permeable carrier peptides are currently of interest for their potential to improve the delivery of bioactive molecules into cells and to specific cellular compartments. We have investigated the activity of a derivative of the antiandrogen drug, bicalutamide, attached to the cell-permeable carrier peptide penetratin(R). We have used both disulfide (labile) and thioether (nonlabile) linkages to attach the bicalutamide derivative to the peptide in order to assess whether one type of chemistry has advantages over the other. In addition we have added a nuclear localization sequence (NLS) to the carrier peptide to investigate whether localization of the drug to the nucleus of the cell affects the activity of the drug. Biotin-labeled peptides were used to demonstrate that the carrier peptide is rapidly accumulated inside cultured cells, and that the incorporation of an NLS in the sequence results in its nuclear targeting. The bicalutamide derivative linked to carrier peptides via a disulfide-linkage exerted no greater antiproliferative effect in LNCaP cells, than the bicalutamide derivative alone. The bicalutamide derivative linked to the carrier peptide by a non-labile thioether linkage showed a similar activity profile. When the construct includes a nuclear targeting sequence, however, a markedly increased antiproliferative effect was observed. This study has thus shown that the activity of bicalutamide may be enhanced by the nonlabile attachment of a cell-permeable and nuclear-targeted peptide, which has implications for the development of novel antiandrogens for the treatment of prostate cancer.
A new view of protein synthesis: mapping the free energy landscape of the ribosome using single-molecule FRET.
Munro JB, Vaiana A, Sanbonmatsu KY … +1 more , Blanchard SC
Biopolymers · 2008 Jul · PMID 18286627 · Full text
This article reviews the application of single-molecule fluorescence resonance energy transfer (smFRET) methods to the study of protein synthesis catalyzed by the ribosome. smFRET is a powerful new technique that can be...
This article reviews the application of single-molecule fluorescence resonance energy transfer (smFRET) methods to the study of protein synthesis catalyzed by the ribosome. smFRET is a powerful new technique that can be used to investigate dynamic processes within enzymes spanning many orders of magnitude. The application of wide-field smFRET imaging methods to the study of dynamic processes in the ribosome offers a new perspective on the mechanism of protein synthesis. Using this technique, the structural and kinetic parameters of tRNA motions within wild-type and specifically mutated ribosome complexes have been obtained that provide valuable new insights into the mechanism and regulation of translation elongation. The results of these studies are discussed in the context of current knowledge of the ribosome mechanism from both structural and biophysical perspectives.
Cell (A549)-particle (Jasada Bhasma) interactions using Raman spectroscopy.
Pyrgiotakis G, Bhowmick TK, Finton K … +4 more , Suresh AK, Kane SG, Bellare JR, Moudgil BM
Biopolymers · 2008 Jun · PMID 18253947 · Publisher ↗
Current methods for the evaluation of cell interactions with particles are nonspecific, slow, and invasive to the cells. Raman spectroscopy is a noninvasive technique, and is used in the present study to investigate part...
Current methods for the evaluation of cell interactions with particles are nonspecific, slow, and invasive to the cells. Raman spectroscopy is a noninvasive technique, and is used in the present study to investigate particle-cell interactions. The main focus of the present study is to employ Raman spectroscopy for investigating the interaction of human lung adenocarcinoma cell line (A549) with the particulate system Jasada Bhasma, a traditional Indian medicine. Jasada Bhasma is a unique preparation of zinc and is traditionally used for the treatment of various diseases like diabetes, age-related eye diseases, and as a health promotional tonic. The Raman spectral analysis is executed by identifying the difference in intracellular DNA/RNA, and proteins and lipids concentration between particles--treated and untreated cells. Comparison between Bhasma-treated and -untreated cells indicates that vibrational peaks corresponding to the DNA/RNA molecule show a significant increase in cells treated with the Jasada Bhasma. Apart from the DNA molecule, several other vibrational peaks related to the protein molecules also show a significant increase in A549 cells after treatment with Bhasma. These results indicate that Bhasma treatment of A549 possibly delays DNA degradation and enables retention of higher amount of protein molecules in the cells.
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