Wray J W, Abeles R H
Graduate Department of Biochemistry, Brandeis University, Waltham, Massachusetts 02254.
J Biol Chem. 1993 Oct 15;268(29):21466-9.
We have isolated and purified an enzyme (E-2) from Klebsiella pneumoniae, which catalyzes the formation of CO from CH3-S-CH2-CH2-CO-C(OH) = CH-O- (III). This compound is an intermediate in the conversion of 5'-methylthioadenosine to methionine. Concomitant with CO formation, methylthiopropionic acid and formate are produced and O2 is consumed. E-2 also catalyzes the formation of CO, formate, and butyrate from CH3-CH2-CH2-CO-C(OH) = CH-O- (IIIa), the desthio analog of III. Experiments with isotopic IIIa have shown that formate is derived from 1-C, and CO from 2-C. E-2 has a M(r) = 18,500 and requires Mg2+, and no chromophoric cofactor has been detected.
我们从肺炎克雷伯菌中分离并纯化了一种酶（E-2），它催化由CH3-S-CH2-CH2-CO-C(OH)=CH-O-（III）形成CO。该化合物是5'-甲硫基腺苷转化为甲硫氨酸过程中的一个中间体。在形成CO的同时，会产生甲硫基丙酸和甲酸，并消耗O2。E-2还催化由CH3-CH2-CH2-CO-C(OH)=CH-O-（IIIa），即III的脱硫类似物形成CO、甲酸和丁酸。用同位素IIIa进行的实验表明，甲酸来自1-C，CO来自2-C。E-2的相对分子质量为18,500，需要Mg2+，且未检测到发色辅因子。
