Conformational studies polypeptides

Kleier, D. A., and W. N. Lipscomb. 1977. Molecular Orbital Study of Polypeptides. Conformational and Electronic Structure of Polyglycine. Int. J. Quantum Chem. Quantum Biol. Symp. 4, 73-86. 

In one case, a small peptide with enzyme-like capability has been claimed. On the basis of model building and conformation studies, the peptide Glu-Phe-Ala-Ala-Glu-Glu-Phe-Ala-Ser-Phe was synthesized in the hope that the carboxyl groups in the center of the model would act like the carboxyl groups in lysozyme 17). The kinetic data in this article come from assays of cell wall lysis of M. lysodeikticus, chitin hydrolysis, and dextran hydrolysis. All of these assays are turbidimetric. Although details of the assay procedures were not given, the final equilibrium positions are apparently different for the reaction catalyzed by lysozyme and the reaction catalyzed by the decapeptide. Similar peptide models for proteases were made on the basis of empirical rules for predicting polypeptide conformations. These materials had no amidase activity and esterase activity only slightly better than that of histidine 59, 60). 

AOT/isooctane Protamines from sperm head nucleoproteins of fish Conformational studies on model polypeptides with amino acid sequences similar to clupeine and salmine were carried out in RMs [286]... 

Wada 109, 110) pioneered studies of polypeptide conformation by the dielectric method. He found 110) a linear dependence of (ft2)1 2 on Mw for a series of PBLG samples (ranging from 7 x 104 to 18 x 104 in Mw) in EDC at 25° C and obtained 3.5 D for gh, where D stands for debye units. He computed (ft2) by the use of an approximate equation derived by himself 109) for rigid-rod molecules, which for very dilute solutions may be written... 

A Conformational Study of the l-Alanine Residue in Polypeptides by Ab Initio UC NMR Shielding Calculation... 

A. Anderson, M. Carson, and J. Hermans, Ann. N.Y. Acad. Sci., 482,51 (1986). Molecular Dynamics Simulation Study of Polypeptide Conformational Equilibria A Progress Report. 

Mezo, G., Kajtar, J., Nagy, I., Szekerke, M., and Hudecz, F. (1997) Carrier design Synthesis and conformational studies of poly[L-lysine] based branched polypeptides with hydroxyl groups. Biopolymers 42, 719-730. 

We have seen in the preceding discussion that the properties of enzymes depend critically on the existence of a well-defined conformation of the polypeptide chain. Studies that have been carried out so far with synthetic chain molecules employed materials composed of molecules which may assume, in solution, a very large number of conformations with comparable probability. Investigations of this type may be divided into three groups ... 

Fig. 14. A dipeptide and standard conventions for the study of polypeptide conformations...

Conformational study of natural fibrous proteins and their model polypeptides by H CRAMPS NMR... 

It is not our intention to review the entire field of iron proteins. Rather, we will focus on certain cases for which the experimental evidence concerning the conformational consequences of the iron-polypeptide interaction are well established. Stereochemical aspects of metallo-porphyrins have recently been surveyed (6) and some conformational studies on haemoproteins were elegantly presented by Wuthrich in this series (7). We will also ignore ferritin, where iron is non-structural but is present as a micellar aggregate of mixed hydroxide-phosphate salt coated by 20—24 globular protein units (8) (See the review by R. R. Crichton in this issue). 

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