Kundu G C, Wilson I B
Department of Chemistry and Biochemistry, University of Colorado, Boulder.
Int J Pept Protein Res. 1993 Jul;42(1):64-7. doi: 10.1111/j.1399-3011.1993.tb00351.x.
The metal ion of endothelin-converting enzyme (ECE) was investigated by inhibiting the enzyme with ethylenediaminetetraacetic acid (EDTA) and restoring activity by adding divalent metal salts in quantities less than the concentration of EDTA. Under these conditions, only metal ions that bind to ECE with high affinity can affect the enzyme. The ferrous enzyme had an activity of 76% relative to the native enzyme, the manganous enzyme 76%, the nickelous enzyme 77%, the cupric enzyme 17%, the zinc enzyme 98% and the cobaltous enzyme 122%. Of these first transition series elements only zinc can be the metal of the native enzyme. The zinc enzyme has the same Km and turnover number as the native enzyme.
通过用乙二胺四乙酸（EDTA）抑制内皮素转化酶（ECE）并添加量少于EDTA浓度的二价金属盐来恢复活性，研究了该酶的金属离子。在这些条件下，只有以高亲和力与ECE结合的金属离子才能影响该酶。亚铁酶的活性相对于天然酶为76%，锰酶为76%，镍酶为77%，铜酶为17%，锌酶为98%，钴酶为122%。在这些第一过渡系元素中，只有锌可以是天然酶的金属。锌酶与天然酶具有相同的米氏常数（Km）和周转数。
