Premium
The effect of the L ‐azetidine‐2‐carboxylic acid residue on protein conformation. IV. Local substitutions in the collagen triple helix
Author(s) -
Zagari Adriana,
Palmer Kathleen A.,
Gibson Kenneth D.,
Némethy George,
Scheraga Harold A.
Publication year - 1994
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.360340107
Subject(s) - triple helix , chemistry , tripeptide , collagen helix , helix (gastropod) , residue (chemistry) , stereochemistry , substitution (logic) , crystallography , peptide , biochemistry , ecology , snail , computer science , biology , programming language
The properties of collagen are affected by the replacement of Pro by imino acid analogues. The structural effect of the low‐level local substitution of L ‐azetidine‐2‐carboxylic acid (Aze) has been analyzed by computing the energy of CH 3 CO‐(Gly‐Pro‐Pro) 4 ‐NHCH 3 triple helices in which a single residue of one strand has been replaced by Aze. When Aze is in position Y of a (Gly‐X‐Y) unit, low‐energy local deformations are introduced in the triple helix, i.e., it becomes more flexible. On the other hand, the flexibility of the triple helix is not increased with Aze in position X. The energy of the triple helix to coil transition is not changed significantly by this amount of substitution. In an earlier study, we have demonstrated that the regular substitution of Aze in every tripeptide distorts or destabilizes the triple helix to a large extent [A. Zagari, G. Némethy, & H. A. Scheraga (1990) Biopolymers , Vol. 30, pp. 967–974 ]. Thus, it appears that a high level of substitution is required to cause the observed chemical and biological effects of Aze on collagen. © 1994 John Wiley & Sons, Inc.