Studies on the inhibitory mechanism of soybean trypsin inhibitors by the chemical change of amino acid residues.

通过氨基酸残基的化学变化研究大豆胰蛋白酶抑制剂的抑制机制。

• 批准号: 62470149
• 负责人: IKENAKA Tokuji
• 金额: $ 2.5万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 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/en/grant/KAKENHI-PROJECT-62470149/
• 关键词: Trypsin inhibitor; Inhibitory mechanism; アミノ酸残基の化学的変換

Trypsin inhibitors could be reconstituted by mixing the protein moieties and the peptide moieties (from position 64 to position 84) separated from two enzymatically modified soybean trypsin inhibitors by the mutual exchange. A reconstituted inhibitor which has tyrosine at position 62 and histidine at position 71 showed the highest inhibitory activity with Ki value of approximately 10^<-10> M. An inhibitor having phenylalanine and asparagine at positions 62 and 71, respectively, showed the weakest inhibitory activity with Ki value of about 10^<-8> M. Inhibitors possessing either tyrosine at position 62 or histidine at position 71 had Ki value of about 10^<-9> M. Other inhibitors were reconstituted by mixing the protein moieties and synthetic peptides. The replacements of serine residue at position 74 to arginine, and methionine at position 84 to methionine sulfoxide did not affect on Ki values, indicating that they are not concerned directly in contacting with trypsin. No inhibitory activity was observed when the protein moieties were mixed with a synthetic peptide lacking His(71), Pro(72) and Leu(73) residues.

胰蛋白酶抑制剂可以通过混合通过相互交换而从两种酶促修饰的大豆胰蛋白酶抑制剂分离的蛋白质部分和肽部分（从位置64到位置84）来重构。在62位具有酪氨酸和在71位具有组氨酸的重构抑制剂显示出最高的抑制活性，Ki值约为10^-10M。分别在62位和71位具有苯丙氨酸和天冬酰胺的抑制剂显示出最弱的抑制活性，Ki值约为10^-8M。在62位具有酪氨酸或在位置具有组氨酸的抑制剂71 有 Ki值约为10^-9M。通过混合蛋白质部分和合成肽来重构其他抑制剂。将第74位的丝氨酸残基替换为精氨酸，将第84位的甲硫氨酸替换为甲硫氨酸亚砜，对Ki值没有影响，表明它们不直接与胰蛋白酶接触。当蛋白质部分与缺少 His(71)、Pro(72) 和 Leu(73) 残基的合成肽混合时，没有观察到抑制活性。

项目成果

原三郎,池中徳治: "タンパク質II.構造と機能編(勝部幸輝,京極好正,崎正文夫,高木俊夫,中川八郎編)第4章「セリンプロテイナーゼインヒビター」(P.100〜130)" 東京化学同人, 426 (1988)

原三郎、池中德二：《蛋白质 II. 结构与功能（胜部幸辉、京极吉正、崎正文雄、高木俊夫、中川八郎编）第 4 章“丝氨酸蛋白酶抑制剂”（P.100-130）》东京化学同人，426（1988）

Saburo Hara and Tokuji Ikenaka: "Serine proteinase inhibitors" in "The protein II. Structure and protein" (Y. Katsube et al. eds.) 100-130. Tokyo Kagaku Dojin, (1988)

Saburo Hara 和 Tokuji Ikenaka：“蛋白质 II. 结构和蛋白质”中的“丝氨酸蛋白酶抑制剂”（Y. Katsube 等人编辑）100-130。

原三郎,池中徳治: "タンパク質II.構造と機能 編第4章「セリプロテイナーゼインヒビター」" 東京化学同人, 426 (1988)

原三郎、池中德二：“蛋白质 II.结构与功能第 4 章“丝氨酸蛋白酶抑制剂”东京化学同人，426（1988）