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Prolyl isomerization: How significant for in vivo protein folding?
Author(s) -
Wetlaufer Don B.
Publication year - 1985
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.360240119
Subject(s) - chemistry , isomerization , peptide , protein folding , folding (dsp implementation) , in vivo , residue (chemistry) , biophysics , covalent bond , elongation , stereochemistry , phi value analysis , peptide bond , crystallography , biochemistry , organic chemistry , materials science , microbiology and biotechnology , ultimate tensile strength , electrical engineering , metallurgy , biology , engineering , catalysis
Suggestive but not decisive evidence indicates that in vivo peptide chain folding is completed in a time not much longer than that required for covalent peptide synthesis. Extrapolation of model peptide rates of the cis – trans prolyl isomerization leads to the prediction tht protein folding should be much slower than the apparent in vivo rates. On the assumption that rapid protein folding in vivo is the rule, three routes are suggested by which a protein undergoing biosynthesis can avoid a strongly slowed folding rate: (1) by a peptide chain‐elongation process that adds only trans peptide bonds, follwed by a rapid folding process that incorporates them into a three‐dimensional structure, raising the energy barrier to isomerization; (2) by folding to produce three dimensional structures that position prolyl residues largely in chain turns on the protein surface, where the residue may be either cis or trans without large effects on the protein structure and function; (3) prolyl cis – trans isomerization may be speeded by the formation of peptide loops.