Brindle N J, North A C, Brown S B
Biochem J. 1986 May 15;236(1):303-6. doi: 10.1042/bj2360303.
Degradation in vitro of the haem in catalase by a 'coupled oxidation' reaction yields products in which approx. 45% of the haem groups have been cleaved at the alpha-methene bridge, 55% at the beta-bridge and a trace at the delta-bridge. Molecular-mechanics calculations with the three-dimensional structural co-ordinates of catalase shows that these proportions of products can be accounted for by the relative accessibility of the four methene bridges to a haem-linked oxygen molecule, thus further confirming Brown's [(1976) Biochem. J. 159, 23-27] hypothesis that the first stage of haem catabolism in vivo is selective attack by haem-bound oxygen, with selectivity conferred by the surrounding protein moiety.
通过“偶联氧化”反应，过氧化氢酶中的血红素在体外降解产生的产物中，约45%的血红素基团在α-次甲基桥处被裂解，55%在β-桥处被裂解，在δ-桥处有微量裂解。利用过氧化氢酶的三维结构坐标进行的分子力学计算表明，这些产物比例可以通过四个次甲基桥对与血红素相连的氧分子的相对可及性来解释，从而进一步证实了布朗[(1976)《生物化学杂志》159, 23 - 27]的假设，即体内血红素分解代谢的第一阶段是血红素结合的氧的选择性攻击，这种选择性由周围的蛋白质部分赋予。
