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Inhibition Mechanism and Molecular Evolution of Amylase- and Protease-Inhibitors

淀粉酶和蛋白酶抑制剂的抑制机制和分子进化

基本信息

批准号：
62580114
负责人：
ODANI Shoji
金额：
$ 1.09万
依托单位：
Niigata University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1988
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-62580114/
关键词：
Protease amylase inhibitor molecular evolution アミノ酸分析

项目摘要

Based on our previous finding of an extraordinary dicergent evolution that Hordeum uulgare (barley) trypsin inhibitor is structurally related to Triticum (wheat) -amylase inhibitors, Ricinus communis(castor bean) seed strage protein, and mammalian pancreatic secretory trypsin inhibitors, we have investigated the structure-function relationship and molecular evelution of these proteins. Detailed comparison of these inhibitors suggested that they have arisen from fusion of two ancestral genes coding for a proteinase inhibitor and an -amylase inhibitor of about 7 kda in tandem, and subsequent mutation had made one of the inhibitory site silent or specific for some unknown enzymes. This domain structure was partially confirmed by determination of 3 (out of 5) disulfide bridges in the barley inhibitor. It is of particular interest that the potential -amylase inhibitory domain is also homologous to bovine pancreatic secretory trypsin inhibitor (kazal), indicating the unusual dicergent evolut … More ion of a proteinase- and an -amylase-inhibitors from a single ancestral gene.Plant seeds contain a number of low nolecular mass proteins of known and unknown function. We have identified an unusually hydrophobic protein in glycine max (soybean) seeds, and determined the complete primary structure. The protein showed a very weak inhibitory action on mammalian triacylglycerol lipases, and also a weak and partial sequence similarity to the above described proteins and to bowman-birk type inhibitors, which suggest the presence of a protein superfamily including a wide variety of proteins. It also showed a marked and unexpected similarity to a mammalian hormone, rat prolaction. Another unusual protein, soybean aspartic acid-rich polypeptide, has been isolated and sequence. The protein is remarkable for its high content of aspartic acid, and sequence analysis showed that the protein has a long poly(L-aspartic acid) tail at the C-terminus which interacts with trypsin.Post-translational modifications, important for manifestation of protein fonctions, is rather difficult to detect by the ordinary analytical systems. We have constructed a rapid and sensitive detection system for modified amino acids and applied to the present investigation. Less

基于我们先前发现的大麦胰蛋白酶抑制剂与小麦淀粉酶抑制剂、蓖麻种子蛋白和哺乳动物胰腺分泌胰蛋白酶抑制剂在结构上有着非常相似的进化关系，我们研究了这些蛋白的结构-功能关系和分子进化。这些抑制剂的详细比较表明，它们是由编码蛋白酶抑制剂和淀粉酶抑制剂的两个祖先基因串联融合而产生的，随后的突变使其中一个抑制位点沉默或特异于某些未知酶。通过测定大麦抑制剂中的3个（共5个）二硫键，部分证实了该结构域结构。特别令人感兴趣的是，潜在的-淀粉酶抑制结构域也与牛胰腺分泌性胰蛋白酶抑制剂（kazal）同源，表明不寻常的双切进化。 ...更多信息来自单一祖先基因的蛋白酶和淀粉酶抑制剂离子。植物种子含有许多功能已知和未知的低分子量蛋白质。我们在大豆种子中发现了一种异常疏水的蛋白质，并确定了其完整的一级结构。该蛋白质对哺乳动物三酰甘油脂肪酶显示出非常弱的抑制作用，并且与上述蛋白质和bowman-birk型抑制剂也显示出弱的和部分的序列相似性，这表明存在包括多种蛋白质的蛋白质超家族。它还显示出与哺乳动物激素大鼠催乳素的显著和意想不到的相似性。另一种不寻常的蛋白质，大豆富含天冬氨酸的多肽，已被分离和测序。该蛋白质的特点是天冬氨酸含量高，序列分析表明该蛋白质的C端有一个长的聚L-天冬氨酸尾，它能与胰蛋白酶相互作用，而翻译后修饰是蛋白质功能的重要表现，用普通的分析系统很难检测到。我们建立了一个快速、灵敏的修饰氨基酸检测体系，并应用于本研究。少