Coacervation properties in sequential polypeptide models of elastin. Synthesis of H-(Ala-Pro-Gly-Gly)n-Val-OMe and H-(Ala-Pro-Gly-Val-Gly)n-Val-OMe.
Syntheses of two sequential polypeptides H-(Ala-Pro-Gly-Gly)n-Val-OMe and H-(Ala-Pro-Gly-Val-Gly)n-Val-OMe via the p-nitrophenyl active ester procedure are reported. The two polymers were obtained in good yields and the polymers were shown to be of large molecular weights, n greater than 40. These two polypeptides were synthesized as analogs of the two coacervating sequential polypeptides H-(Val-Pro-Gly-Gly)n-Val-OMe, and H-(Val-Pro-Gly-Val-Gly)n-Val-OMe, in which the Val-l residue is replaced by an Ala-l residue. H-(Ala-Pro-Gly-Gly)n-Val-OMe did not coacervate even at as high a temperature as 100 degrees, and H-(Ala-Pro-Gly-Val-Gly)n-Val-OMe did not coacervate; however, it precipitated irreversibly around 65--70 degrees C. This suggests the critical role of the Val-Pro hydrophobic side chain interaction in coacervation.
D000595:Amino Acid Sequence; D004549:Elastin; D008722:Methods; D009842:Oligopeptides / Q000138:chemical synthesis*; D010455:Peptides / Q000138:chemical synthesis*; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D013696:Temperature
D009842:Oligopeptides; D010455:Peptides; D004549:Elastin