title: NMR observations of 13C-enriched coenzyme B12 bound to the ribonucleotide reductase from Lactobacillus leichmannii.
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.
authors.affiliation: Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701, USA. brownk3@ohiou.edu
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Brown
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Xiang
authors.initials: X
authors.lastname: Zou
mesh_terms: D002247:Carbon Isotopes; D003038:Cobamides / Q000737:chemistry* / Q000378:metabolism*; D003839:Deoxyadenosines / Q000737:chemistry / Q000378:metabolism; D052199:Lactobacillus leichmannii / Q000201:enzymology*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D012264:Ribonucleotide Reductases / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D002247:Carbon Isotopes; D003038:Cobamides; D003839:Deoxyadenosines; C033714:5'-deoxyadenosine; D012264:Ribonucleotide Reductases