Coenzyme B12‐dependent 2‐methyleneglutarate mutase from Clostridium barkeri Protection by the substrate from inactivation by light

FEBS Letters

Michel, C.¹  Buckel, W.¹ 

[1] Laboratorium für Mikrobiologie, Fachbereich Biologie, Philipps-Universität, W-3550 Marburg, Germany

关键词: Coenzyme B12;    Adenosylcobalamin;    2-Methyleneglutarate mutase;    Visible light;    Clostridium barkeri;    Co–C bond cleavage;   

DOI  :  10.1016/0014-5793(91)80370-I

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Partially purified 2-methyleneglutarate mutase from Clostridium barkeri was separated from 3-methylitaconate Δ-isomerase by treatment with 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS) followed by FPLC on the anion exchange column Mono Q in the presence of the detergent. When purified in the dark, the active mutase contained a corrinoid, most probably coenzyme B₁₂. The enzyme was inactivated by light at the same wavelength (λ < 620 nm) and rate as free coenzyme B₁₂. The rate was not influenced by oxygen or by temperature (O=37°C). Reactivation of up to 50% of the original activity was achieved by incubation with coenzyme B₁₂ and diathiothreitol. The substrates 2-methyleneglutarate (up to 40mM) or (R)-3-methylitaconate specifically protected the enzyme from inactivation by visible light. This effect as enhanced 3-fold by raising the temperature from 0°C to 37°C. The data indicate that during catalysis, the Co–C bond of the coenzyme is cleaved and cannot be affected any more by light.

【 授权许可】

Unknown