家蚕抑前胸腺肽类似物的活性鉴定和结构分析

以家蚕Bombyx mori抑前胸腺肽的氨基酸序列作为基础，通过氨基酸残基的添加、减少和置换，人工合成了一组与家蚕抑前胸腺肽结构类似的多肽。利用家蚕前胸腺体外培养技术，结合蜕皮激素放射免疫分析方法，鉴定了与抑前胸腺肽结构类似的多肽的生理活性，并对它们的活性特征、化学参数、结构和功能、信号传导途径进行了综合的比较和分析。类似物899808的生物学功能与抑前胸腺肽的相同而且活性近似；类似物899805和899809对家蚕前胸腺蜕皮激素的生物合成表现出随浓度增加而增加的促进作用，而低浓度下几乎不促进；899803、899804、899806和899807类似物对家蚕前胸腺蜕皮激素的生物合成的促进和抑制作用与它们的浓度有着依赖关系。实验结果表明，对抑前胸腺肽的氨基酸序列作任何改变，都导致其生理活性的下降、丧失甚至相反的活性。

Activity identification and structure analysis of the analogs of prothoracicostatic peptide of the silkworm, Bombyx mori

Based on the amino acid sequence of prothoracicostatic peptide of the silkworm, Bombyx mori, a group of analogs of Bom-PTSP were synthesized by chemical modifications, such as adding, removing, exchanging amino acid of the peptide. By using silkworms' prothoracic glands in vitro culture and 3H-ecdysteriod-radioimmunoassay, the biological activities of those analogs were examined, and their activation features, chemical parameters, and the relationship between structure and function of those peptides were compared and analyzed. It was found the analog 899808 had the same biological function and the similar activity as Bom-PTSP. The analogs 899805 and 899809 partially stimulated ecdysteroidogenesis in a dose dependent manner, while 899803, 899804, 899806 and 899807 had both stimulatory and inhibitory effects on ecdysteroidogenesis, depending on concentration. A possible mechanism of biological activity of Bom-PTSP was discussed.