Grandt D, Schimiczek M, Struk K, Shively J, Eysselein V E, Goebell H, Reeve J R
Department of Gastroenterology, University of Essen, Germany.
Peptides. 1994;15(5):815-20. doi: 10.1016/0196-9781(94)90035-3.
Peptide YY (PYY) has been purified as a 36 amino acid peptide from intestinal extracts of several mammalian species including pig, rat, dog, and man. The primary structure of rabbit PYY is still unknown, although rabbit tissues have extensively been used for characterization of PYY receptor subtypes and receptor subtype-mediated actions. We report the purification and primary structure of PYY(1-36) (PYY-I) from rabbit intestinal mucosa, and the existence of a second endogenous molecular form of PYY, PYY(3-36) (PYY-II). The amino acid sequence of PYY-I is YPSKPEAPGEDASPEELNRYYASLRHYLNLVTRQRY-amide. Rabbit PYY differs from porcine PYY, which is identical to rat and canine PYY, by two amino acid substitutions at positions 3 (Ser instead of Ala) and 18 (Asp instead of Ser), whereas rabbit PYY and human PYY differ by only one residue at position 3 (Ser instead of Ile). The existence of two endogenous forms of PYY in the rabbit, with PYY-II lacking the amino-terminal dipeptide Tyr-Pro of PYY-I, is consistent with previously reported findings, demonstrating the existence of PYY-II in man and dog (9,11). We have previously demonstrated that PYY-I is an unselective Y1/Y2 agonist, whereas PYY-II is a highly selective Y2 agonist. Thus, proteolytic processing of PYY-I controls the peptide's receptor selectivity. The existence of PYY-I and PYY-II in the rabbit supports the assumption of a physiological role of Y receptor heterogeneity for PYY.
肽YY（PYY）已从包括猪、大鼠、狗和人类在内的几种哺乳动物的肠道提取物中纯化出来，是一种由36个氨基酸组成的肽。尽管兔组织已广泛用于表征PYY受体亚型和受体亚型介导的作用，但兔PYY的一级结构仍然未知。我们报告了从兔肠黏膜中纯化出的PYY(1-36)（PYY-I）及其一级结构，以及PYY的第二种内源性分子形式PYY(3-36)（PYY-II）的存在。PYY-I的氨基酸序列为YPSKPEAPGEDASPEELNRYYASLRHYLNLVTRQRY-酰胺。兔PYY与猪PYY不同，猪PYY与大鼠和犬PYY相同，兔PYY在第3位（丝氨酸代替丙氨酸）和第18位（天冬氨酸代替丝氨酸）有两个氨基酸替换，而兔PYY和人PYY仅在第3位有一个残基差异（丝氨酸代替异亮氨酸）。兔体内存在两种内源性PYY形式，PYY-II缺少PYY-I的氨基末端二肽Tyr-Pro，这与先前报道的结果一致，证明人和狗体内存在PYY-II(9,11)。我们先前已证明PYY-I是一种非选择性的Y1/Y2激动剂，而PYY-II是一种高度选择性的Y2激动剂。因此，PYY-I的蛋白水解加工控制了该肽的受体选择性。兔体内PYY-I和PYY-II的存在支持了PYY的Y受体异质性具有生理作用这一假设。
