Matsunaga T O, Castrucci A M, Hadley M E, Hruby V J
Department of Chemistry, University of Arizona, Tucson 85721.
Peptides. 1989 Mar-Apr;10(2):349-54. doi: 10.1016/0196-9781(89)90042-9.
Nineteen analogues of melanin concentrating hormone (MCH) were synthesized and tested for their skin-lightening activities in the in vitro eel skin (Synbranchus marmoratus) bioassay. All the analogues synthesized were fragments of the native sequence: Asp-Thr-Met-Arg-Cys-Met-Val-Gly-Arg-Val-Tyr-Arg-Pro-Cys-Trp-Glu-Val with sequential elimination of substituents from both the carboxy- and amino-termini. All the analogues that contained tryptophan in position 15 were found to be full agonists and equipotent to MCH. In the absence of Trp15, full agonist activity was maintained but potency was reduced ten-fold or more. The minimal fragment analogue possessing equipotency to the parent peptide, MCH, was the MCH(5-15) sequence. These observations coupled with results from work reported previously by our laboratories suggest the importance of the Trp15 residue for interaction with the MCH receptor in this assay system.
合成了19种黑色素聚集激素（MCH）类似物，并在体外鳗鱼皮肤（斑点裸胸鳝）生物测定中测试了它们的美白活性。所有合成的类似物都是天然序列Asp-Thr-Met-Arg-Cys-Met-Val-Gly-Arg-Val-Tyr-Arg-Pro-Cys-Trp-Glu-Val的片段，从羧基末端和氨基末端依次去除取代基。发现所有在第15位含有色氨酸的类似物都是完全激动剂，且与MCH等效。在没有Trp15的情况下，仍保持完全激动剂活性，但效价降低了十倍或更多。与亲本肽MCH等效的最小片段类似物是MCH(5-15)序列。这些观察结果与我们实验室先前报道的工作结果相结合，表明在该测定系统中，Trp15残基对于与MCH受体相互作用很重要。
