猪肾胆绿素还原酶活性基团的修饰

猪肾胆绿素还原酶活性基团的修饰 MODIFICATION FOR THE ACTIVITY OF PIG KIDNEY BILIVERDIN REDUCTASE 张楚富 1 first-author 吴志平 1 武汉大学生命科学学院 武汉大学生命科学学院 School of Life Sciences,Wuhan University School of Life Sciences,Wuhan University 报道采用专一性试剂ＤＴＮＢ、ＮＥＭ、磷酸吡哆醛以及２，３－丁二酮对胆绿素还原酶活性进行修饰．当这几种试剂分别与该酶反应后，酶活性大幅度降低；而当预先加入ＮＡＤＰＨ或胆绿素，酶活性明显受到保护．这些结果表明，半胱氨酸、赖氨酸和精氨酸残基与该酶同ＮＡＤＰＨ和胆绿素结合、以及胆绿素还原成胆红素的反应有关，是该酶活性必需的基团 Pig-kidney biliverdin reductase activity was greatly reduced when the enzyme was treated with thiol reagents, 5, 5′-dithiobis （2-nitrobenzoic acid） （DTNB） and N-ethylmaleimide （NEM）. However, the pretreatment of this enzyme with NADPH or biliverdin partly protected the reductase from the inactivation. When the enzyme was treated with pyridoxal phosphate,which was the modified reagent of lysine residue,the catalytic activity of the enzyme was lowered. Butanedione could specifically reacted to the arginine residue.The reductase.activity was markedly reduced after the enzyme was treated with butanedione, this inhibition was omissive when the pretreatment of enzyme with NADPH but biliverdin. These results showed that cysteine,lysine,and arginine residues were essential for the enzymatic activity of the biliverdin reductase. 胆绿素还原酶 活性必需基团 酶修饰 pig-kidney biliverdin reductase active site enzyme modification Q554.9 国家自然科学基金(61672102) 1995-02-01 2021-04-01 2