Abstract |
The triple-helical conformation has the stringent amino acid sequence constraint that every third residue must be a glycine, (X-Y-Gly)n. We use nuclear magnetic resonance and circular dichroism to quantify the consequences of a substitution in the glycine position of a triple-helical peptide, and to enhance our understanding of interactions in this basic structural motif. A 30-residue peptide with a Gly----Ala change forms a stable trimer at a folding rate somewhat less than that of the unsubstituted peptide, and the substitution results in a marked decrease in thermal stability and a conformational perturbation of about 30% of the triple-helical structure. Two models were generated for this peptide, one with the alanine residues packed inside the triple helix and one with a looping out of the chain at the substitution site. Studies on the Gly----Ala peptide are useful in understanding connective tissue diseases which result from the substitution of one glycine residue in the triple-helix of fibrillar collagens.
|
Authors | C G Long, M H Li, J Baum, B Brodsky |
Journal | Journal of molecular biology
(J Mol Biol)
Vol. 225
Issue 1
Pg. 1-4
(May 05 1992)
ISSN: 0022-2836 [Print] Netherlands |
PMID | 1583683
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)
|
Chemical References |
|
Topics |
- Circular Dichroism
- Glycine
(chemistry)
- Kinetics
- Magnetic Resonance Spectroscopy
- Peptides
(chemistry)
- Protein Conformation
- Temperature
|