期刊論文

標題 Protein-coenzyme Interactions in adenosylcobalamin-dependent glutamate mutase
學年 89
學期 2
出版(發表)日期 2001/07/01
作品名稱 Protein-coenzyme Interactions in adenosylcobalamin-dependent glutamate mutase
作品名稱(其他語言)
著者 Huhta, M.S.; Chen, H.P.; Hemann, C.; Hille, C.R.; Marsh, E.N.
單位 淡江大學化學學系
出版者 London: Portland Press
著錄名稱、卷期、頁數 Biochemical Journal 355(1), pp.131-137
摘要 Glutamate mutase catalyses an unusual isomerization involving free-radical intermediates that are generated by homolysis of the cobalt-carbon bond of the coenzyme adenosylcobalamin (coenzyme B(12)). A variety of techniques have been used to examine the interaction between the protein and adenosylcobalamin, and between the protein and the products of coenzyme homolysis, cob(II)alamin and 5'-deoxyadenosine. These include equilibrium gel filtration, isothermal titration calorimetry, and resonance Raman, UV-visible and EPR spectroscopies. The thermodynamics of adenosylcobalamin binding to the protein have been examined and appear to be entirely entropy-driven, with DeltaS=109 J.mol(-1).K(-1). The cobalt-carbon bond stretching frequency is unchanged upon coenzyme binding to the protein, arguing against a ground-state destabilization of the cobalt-carbon bond of adenosylcobalamin by the protein. However, reconstitution of the enzyme with cob(II)alamin and 5'-deoxyadenosine, the two stable intermediates formed subsequent to homolysis, results in the blue-shifting of two of the bands comprising the UV-visible spectrum of the corrin ring. The most plausible interpretation of this result is that an interaction between the protein, 5'-deoxyadenosine and cob(II)alamin introduces a distortion into the ring corrin that perturbs its electronic properties.
關鍵字 Enzyme;Resonance Raman spectroscopy;Vitamin B 12
語言 英文
ISSN 0264-6021
期刊性質 國外
收錄於
產學合作
通訊作者
審稿制度
國別 英國
公開徵稿
出版型式 紙本