| Abstract: | A number of polytripeptides related to collagen, namely, (Gly-Pro-Pro)n, (Gly-Pro-Hyp)n, (Gly-Hyp-Hyp)n, (Gly-Pro-Ala)n, (Gly-Pro-Leu)n, (Gly-Pro-Gly)n,(Gly-Ala-Pro)n, (Gly-Ala-Hyp)n, (Ala-Pro-Pro)n, and (Ala-Hyp-Hyp)n were investigated by the method of ir spectroscopy and hydrogen-deuterium kinetics. Strength and order of interpeptide hydrogen bonds of the polytripeptides in a triple-helical conformation were found to depend on the amino acid composition and residue sequence in the triplets. Correlation of X-ray diffraction and spectroscopic data for (Gly-Pro-Hyp)n showed that the increase of the helix parameter in the process of dehydration is accompanied with the weakening of interpeptide hydrogen bonds. Influences of bound water on the length and order of interchain hydrogen bonding was also examined. It was shown that the incorporation of water molecules into the triple helix depends on the amino acid composition and residue sequence. Synthetic models and native collagens were compared. |
