Terry A S, Poulter L, Williams D H, Nutkins J C, Giovannini M G, Moore C H, Gibson B W
University Chemical Laboratories, Cambridge, United Kingdom.
J Biol Chem. 1988 Apr 25;263(12):5745-51.
Amphibian skin is well known as a source of peptides homologous to bioactive peptides found in mammalian gut and brain. A systematic investigation of the skin secretions from Xenopus laevis revealed several peptides not derivable from known precursors. The sequence elucidation, utilizing fast atom bombardment/mass spectrometry, of two peptides, PGS and PGS Gly-10;Lys-22, is reported. These have been independently characterized and named magainins and found to have antimicrobial activity. A mixed sequence oligonucleotide probe complementary to the mRNA sequence coding for PGS was synthesized and used to screen a Xenopus skin cDNA library. A full length cDNA species encoding prepro-PGS was isolated and characterized, and its sequence is reported. The deduced precursor sequence was found to contain one copy of PGS Gly-10;Lys-22 and five copies of PGS. The proteolytic processing of this prepro-polypeptide is discussed.
两栖动物的皮肤是与在哺乳动物肠道和大脑中发现的生物活性肽同源的肽的一个众所周知的来源。对非洲爪蟾皮肤分泌物的系统研究揭示了几种并非来自已知前体的肽。本文报道了利用快原子轰击/质谱法对两种肽PGS和PGS Gly-10;Lys-22进行的序列解析。它们已被独立鉴定并命名为蛙皮抗菌肽，且发现具有抗菌活性。合成了与编码PGS的mRNA序列互补的混合序列寡核苷酸探针，并用于筛选非洲爪蟾皮肤cDNA文库。分离并鉴定了编码前体PGS的全长cDNA物种，并报道了其序列。推导的前体序列被发现包含一个PGS Gly-10;Lys-22拷贝和五个PGS拷贝。本文还讨论了这种前体多肽的蛋白水解加工过程。
