Lehnert P, Forell M M, Jaeger E, Moroder L, Wünsch E
Digestion. 1981;22(2):85-8. doi: 10.1159/000198600.
In the dog pancreas in vivo, the biological activity of secretin and vasoactive intestinal peptide was compared to that of secretin analogues modified in their N-terminal hexapeptide and to X-secretion (alpha, beta-Asp3-secretin) and Y-secretin (a conversion product of X-secretin consisting of about 15% secretin and 85% beta-Asp3-secretin). Replacement of Asp3 by glutamic acid reduced secretin activity markedly. Replacement by neutral amino acids abolished the activity nearly completely. alpha, beta-Asp3-secretin and beta-Asp3-secretin appeared to be ineffective. The results indicate that the free beta-carboxy group of the side chain of the Asp3 residue of the secretin molecule is of decisive importance for hydrokinetic action.
在犬胰腺活体中，将促胰液素和血管活性肠肽的生物活性与在其N端六肽处修饰的促胰液素类似物以及X-分泌素（α，β-天冬氨酸3-促胰液素）和Y-分泌素（X-分泌素的一种转化产物，约含15%促胰液素和85%β-天冬氨酸3-促胰液素）的生物活性进行了比较。将天冬氨酸3替换为谷氨酸会显著降低促胰液素活性。替换为中性氨基酸几乎会完全消除活性。α，β-天冬氨酸3-促胰液素和β-天冬氨酸3-促胰液素似乎没有效果。结果表明，促胰液素分子中天冬氨酸3残基侧链的游离β-羧基对促液动力作用起决定性作用。
