五步蛇毒中血管紧张素转换酶抑制剂的研究

ASTUDY ON ANGIOTENSIN COVERTING ENZYME INHIBITOR FROMAGISTRODON ACUTUS VENOM

采用离子交换和凝胶过滤等方法，从中国五步蛇毒（ｖｅｎｏｍｏｆＡｇｋｉｓｔｒｏｄｏｎａｃｕｔｕｓ）中分离提纯出一种血管紧张素转换酶抑制剂（ＡｎｇｉｏｔｅｎｓｉｎＣｏｎｖｅｒｔｉｎｇＥｎｚｙｍｅＩｎｈｉｂｉｔｏｒ，ＡＣＥＩ），名为ＡＩ＿（９３），该抑制剂经豚鼠回肠测定能加强舒缓激肽（Ｂｒａｄｙｋｉｎｉｎ，ＢＫ）的效应，再经高压纸电泳，ＨＰＬＣ和氨基酸组分分析鉴定为１３肽，不含脯氨酸，分子量约为１．４２ＫＤ，ＰＩ约为４．０，得率约是原毒的３．４‰，ＡＣＥ抑制活力测定ＩＣ＿（５０）。浓度为１１．０μｍｏｌ／Ｌ，属竞争性抑制类型，Ｋｉ＝５．８μｍｏｌ／Ｌ。

A new Angiotensin Converting Enzyine Inhibitor(ACEI),AI_(93) ,was isolated and purified from Agistrodon acutus Venom by Sp-sephadex C_(25)ion-exchange and SephadexG_(25),Sephadex G_(10)gel-filtration,The yield of AI_(93)was0.34%。AI_(93)was identified by paperelectrophoresis and high performance liquid Chroniatography(HPLC).Amino acid analysis ofAI_(93),showed that it contained 13 peptides,and without any proline in its amino-acid composi-tion,The molecular weight was estimated to be about 1420 The isoelectric point was about 4.0。The mode of its biochemical action on the inhibition of ACE was competitive in nature,IC(50)=11μmol/ L,Ki=5.8μmol/ L.