Of Polypeptides and Proteins

Ramachandran G N and Sasisekharan V 1968 Conformation of polypeptides and proteins Adv. Prof. Chem. 23 283-438... 

M.J. Sippl, M. Hendlich and P. Lackner, Assembly of polypeptide and protein backbone conformations from low energy ensembles of short fragments. Protein Sci. 1 (1992), 625-640. 

Although the natural abundance of nitrogen-15 [14390-96-6] leads to lower sensitivity than for carbon-13, this nucleus has attracted considerable interest in the area of polypeptide and protein stmcture deterrnination. Uniform enrichment of is achieved by growing protein synthesi2ing cells in media where is the only nitrogen source. reverse shift correlation via double quantum coherence permits the... 

Schaumann T, Braun W, Wilthrich K. The program FANTOM for energy refinement of polypeptides and proteins using a Newton-Raphson minimizer in torsion angle space. Biopolymers 1990 29 679-694. 

III. Survey of Polypeptide and Protein Raman Optical Activity. 59... 

Preliminary accounts of the assignment of polypeptide and protein ROA bands to the various types of structural elements were given in earlier articles (Wilson et al., 1996a Barron et al., 1996 Teraoka et al., 1998). However, with the measurement of many more ROA spectra, some of these early assignments have been revised (Barron et al., 2000) and are still being refined as more data accumulate. 

Ramachandran, G. N., and V. Sasisekharan. 1968. Conformation Of Polypeptides And Proteins. Adv. Protein Chem. 23, 283M38. 

Pullman, B., and A. Pullman. 1974. Molecular Orbital Calculations on the Conformation of Amino Acid Residues of Proteins, Adv. Protein Chem. 28, 347-526. Ramachandran, G. N., and V. Sasisekharan. 1968. Conformation Of Polypeptides And Proteins, Adv. Protein Chem. 23, 283—438. 

Prize in 1963 for inventing a new general method to synthesize important polymers, a method that uncovered much new basic science. A Nobel Prize in 1984 went to Robert Bruce Merrifield for his invention of a general approach to the synthesis of polypeptides and proteins, in a style directly reminiscent of the biological method used in such synthesis. 

J. W. Longworth, Luminescence of polypeptides and proteins, in Excited States ofProteins and Nucleic Acids (R. F. Steiner and I. Weinryb, eds.), pp. 319-484, Plenum Press, New York (1971). 

Optical Rotation and the Conformation of Polypeptides and Proteins Peter Urnes and Paul Doty... 

First, we consider the fluorinated analogues of natural amino acids, where at least one or several hydrogen atoms have been replaced by fluorine atoms. Then we consider amino acids substituted by a fluoroalkyl group, as the sole structural modification, with special focus on a-fluorinated amino acids. Lastly, we give an outline of polypeptides and proteins in which fluorinated amino acids have been incorporated. 

The properties of polypeptides and proteins are determined to a large extent by the chemistry of the side chain groups, which may be summarized briefly as follows. Glycine in a peptide permits a maximum of conformational mobility. The nine relatively nonpolar amino acids-alanine, valine, leucine, isoleucine, proline, methionine, phenylalanine, tyrosine, and tryptophan-serve as building blocks of characteristic shape. Tyrosine and tryptophan also participate in hydrogen bonding and in aromatic aromatic interactions within proteins. 

Very early examples in this area are the predictions that polyethylene should crystallize in a planar zig-zag conformation, poly(oxymethylene) in a helix having nine repeat units per live turns, some isotactic poly(a-olefins) in helices having three repeat units per single turn, and a number of polypeptides and proteins in the now-famous a-helices. All these predictions, and many others, have been confirmed experimentally.39... 

The procedures and calculations described in this chapter provide considerable insight into the factors affecting the conformations of polypeptides and proteins. The computer programs for gramicidin-S, oxytocin, vasopressin, etc., can also be used for larger structures—of the size of ribonuclease and lysozyme—although the required computer time is considerably increased. 

An enormous work done in the field of polypeptides and proteins by Scheraga and coworkers includes calculations of both conformational energies and enzyme-substrate interactions for this special class of compounds 11 "13 . This kind of calculations on host-guest systems is well documented elsewhere and is not considered within the scope of this article. 

Biochemists say that the two amino acids are connected by a peptide bond, but, of course, the peptide bond is just an amide bond. A slightly more complex example, the phagocytosis-stimulating tetrapeptide known as tuftsin, derived from four amino acids, can be employed to illustrate some of the conventions that are used in writing the structures of polypeptides and proteins ... 

Amino acids are monomeric units of polypeptides and proteins. They are widely used in the food and chemical industries as flavor enhancers, seasonings and sweeteners e.g. for the improvement of bread quality, also in the production of drugs, cosmetics, synthetic leather and surfactants, in medicine for infusions and as therapeutic agents. Amino acids are produced by chemical synthesis or extraction from protein hydrolyzate. They may be also produced by microbiological methods. 

Chapter 3 provides an overview of physicochemical factors that impact analysis and purification of polypeptides and proteins by HPLC techniques. The current status and some of the future challenges facing this major field of separation sciences are considered from both didactic and practical perspectives (Chapter 3). This chapter attempts to provide an overview of terms, concepts, principles, practical aspects, and primary references that underpin the recent developments in this field. Where appropriate, key relationships and dependencies that describe the interactive behavior of polypeptides and proteins with chemically immobilized ligands are discussed. This understanding is central to any subsequent exploration of alternative avenues now available for further research and development into the field of polypeptide or protein purification and analysis. 

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