Takasaki C, Aimoto S, Kitazumi K, Tasaka K, Shiba T, Nishiki K, Furukawa Y, Takayanagi R, Ohnaka K, Nawata H
Department of Chemistry, Faculty of Science, Tohoku University, Sendai, Japan.
Eur J Pharmacol. 1991 Jun 6;198(2-3):165-9. doi: 10.1016/0014-2999(91)90616-x.
The three chimera peptides of sarafotoxins S6b (SRTb) and S6c (SRTc), [Thr2]SRTb, [Asn4]SRTb and [Glu9]SRTb, were synthesized chemically. From the comparisons of lethality, vasoconstrictor activity and receptor binding activity of SRTb, SRTa [( Asn13]SRTb), SRTc [( Thr2,Asn4,Glu9,Asn13]SRTb), [Thr2]SRTb, [Asn4]SRTb and [Glu9]SRTb, it appears that the Lys9 to Glu9 substitution greatly diminishes these activities while the Lys4 to Asn4 substitution does not affect them, and the Ser2 to Thr2 substitution or the Tyr13 to Asn13 substitution slightly diminishes these activities. These results suggest that the very low activities of SRTc are caused mainly by the Lys9 to Glu9 substitution, but not by the Ser2 to Thr2 substitution, which was suggested to be responsible for the weak bioactivities of SRTd [( Thr2,Ile19]SRTb).
化学合成了三种萨拉毒素 S6b（SRTb）和 S6c（SRTc）的嵌合肽，即[Thr2]SRTb、[Asn4]SRTb 和[Glu9]SRTb。通过比较 SRTb、SRTa [（Asn13）SRTb]、SRTc [（Thr2，Asn4，Glu9，Asn13）SRTb]、[Thr2]SRTb、[Asn4]SRTb 和[Glu9]SRTb 的致死性、血管收缩活性和受体结合活性，发现 Lys9 被 Glu9 取代会极大地降低这些活性，而 Lys4 被 Asn4 取代则不影响它们，Ser2 被 Thr2 取代或 Tyr13 被 Asn13 取代会略微降低这些活性。这些结果表明，SRTc 的极低活性主要是由 Lys9 被 Glu9 取代引起的，而不是由 Ser2 被 Thr2 取代引起的，后者曾被认为是 SRTd [（Thr2，Ile19）SRTb]生物活性较弱的原因。
