Mechanism‐Based Inactivation of Coenzyme B
<sub>12</sub>
‐Dependent 2‐Methyleneglutarate Mutase by (
<i>Z</i>
)‐Glutaconate and Buta‐1,3‐diene‐2,3‐dicarboxylate
作者:Wolfgang Buckel、Antonio J. Pierik、Sandra Plett、Ashraf Alhapel、Diana Suarez、Shang‐min Tu、Bernard T. Golding
DOI:10.1002/ejic.200600405
日期:2006.9
(E)-glutaconate, each induced homolysis of the Co–C bond of coenzyme B12 to afford cob(II)alamin and the 5′-deoxyadenosyl radical. The latter probably added to the double bond in (Z)-glutaconate and one of the double bonds in buta-1,3-diene-2,3-dicarboxylate to afford a corresponding “radical adduct”. The formation of new radicals and cob(II)alamin was diagnosed by UV/Visible and EPR spectroscopy. (Z)-Glutaconate
在全 2-亚甲基戊二酸变位酶存在下,buta-1,3-diene-2,3-dicarboxylate 和 (Z)-glutaconate [(Z)-pent-2-ene-1,5-dicarboxylate],但不存在 ( E)-戊二酸,各自诱导辅酶 B12 的 Co-C 键的均裂,以提供 cob(II) 氨基丙酸和 5'-脱氧腺苷自由基。后者可能添加到 (Z)-戊二酸中的双键和 buta-1,3-diene-2,3-dicarboxylate 中的双键之一,以提供相应的“自由基加合物”。通过紫外/可见光和 EPR 光谱诊断新自由基和 cob (II) alamin 的形成。(Z)-Glutaconate 迅速灭活变位酶,形成 aquocobalamin,这可能是通过电子从 cob(II)alamin 转移到自由基加合物而获得的。相比之下,buta-1,3-diene-2,3-dicarboxylate