NMR observations of 13C-enriched coenzyme B12 bound to the ribonucleotide reductase from Lactobacillus leichmannii.

Kenneth L Brown, Jing Li, Xiang Zou

Index: Inorg. Chem. 45(23) , 9172-4, (2006)

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Abstract

The 13C NMR resonance and one-bond 1H-13C coupling constants of coenzyme B12 enriched in 13C in the cobalt-bound carbon have been observed in the complex of the coenzyme with the B12-dependent ribonucleotide reductase from Lactobacillus leichmannii. Neither the 13C NMR chemical shift nor the 1H-13C coupling constants are significantly altered by binding of the coenzyme to the enzyme. The results suggest that ground-state Co-C bond distortion is not utilized by this enzyme to activate coenzyme B12 for C-Co bond homolysis.