赖氨酸残基在鸽肝苹果酸酶核苷酸结合中的作用：用亲和标记高碘酸盐氧化的NADP进行修饰。

Involvement of lysine residue in the nucleotide binding of pigeon liver malic enzyme: modification with affinity label periodate-oxidized NADP.

Chang G G, Chang T C, Huang T M

Int J Biochem. 1982;14(7):621-7. doi: 10.1016/0020-711x(82)90046-5.

Abstract

Periodate-oxidized NADP, a competitive inhibitor of malic enzyme with respect to NADP, inactivate the enzyme in mild conditions. 2. The inactivation is due to the modification of an essential lysine residue. 3. Two molecules of reagent were found to be incorporated into the enzyme tetramer after extensive modification. 4. Complete protection of malic enzyme from the oxidized NADP inactivation was afforded by NADP and its analogues. 5. The modified enzyme showed increased apparent Michaelis constant for the nucleotide coenzymes but the maximum velocity was decreased. 6. The binding between the modified enzyme and NADPH was impaired.

摘要

高碘酸盐氧化的NADP是苹果酸酶相对于NADP的竞争性抑制剂，在温和条件下使该酶失活。2. 失活是由于一个必需赖氨酸残基的修饰。3. 广泛修饰后发现有两分子试剂掺入酶四聚体中。4. NADP及其类似物能完全保护苹果酸酶不被氧化的NADP失活。5. 修饰后的酶对核苷酸辅酶的表观米氏常数增加，但最大速度降低。6. 修饰后的酶与NADPH之间的结合受损。