Stabilization of helical peptides by mixed spaced salt bridges.
J Biomol Struct Dyn
; 14(3): 285-91, 1996 Dec.
Article
in En
| MEDLINE
| ID: mdl-9016406
Whether or not surface salt bridges have a strong stabilizing effect on the native structure in proteins remains uncertain. Previous studies of model peptides have shown that salt bridges spaced at i,i +4 along the chain are more stabilizing than those spaced at i,i +3, with a preference for the order acid-base rather than base-acid from N to C terminus. An analysis of the effect of spacing the ion pairs in short helical peptides is presented, in which acidic and basic side chains spaced two or three residues apart alternate along the chain. The mixed spacing proves to be stabilizing relative to pure spacings. A control peptide in which salt bridges were spaced uniformly three residues apart proved to form a beta-sheet structure rather than alpha-helix. This is due to formation of a silk-like apolar face consisting of alanine side chains; the mesoscopic structure formed by these sheets can be imaged by scanning microscopy.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Peptides
/
Salts
Language:
En
Journal:
J Biomol Struct Dyn
Year:
1996
Document type:
Article
Affiliation country:
United States
Country of publication:
United kingdom