The crystal structure of trifluoromethylcobalamin, a coenzyme B-12 analog

摘要

The X-ray crystal structure of beta-trifluoromethylcobalamin (beta-CF(3)Cbl), a coenzyme B-12 (AdoCbl) analog in which the axial ligand, 5'-deoxyadenosyl in AdoCbl, is replaced by a trifluoromethyl group, has been determined. The beta-CF(3)Cbl crystallizes in the space group P2(1)2(1)2(1) with cell constants a = 15.721 (1), b = 22.781(2), c = 25.010(2) Angstrom, V = 8957(1) Angstrom(3), and four molecules per unit cell. It has an axial Co-N3(Bzm) bond length of 2.05 Angstrom for coordination of the looped-nucleotide to the cobalt atom and a Co-C bond length of 1.88 Angstrom, which are the shortest among normal alkylcobalamins whose X-ray structures have been reported. The corrin ring fold angle along the Co ... C10 axis in CF(3)Cbl is 15.6 degrees. (C) 1998 Elsevier Science S.A. [References: 18]