Investigation of the stereospecificity of clavaminic acid synthase in the desaturation of dihydroclavaminic acid to clavaminic acid
作者:Jack E. Baldwin、Robert M. Adlington、Nicholas P. Crouch、David J. Drake、Yoshiyuki Fujishima、Stephen W. Elson、Keith H. Baggaley
DOI:10.1039/c39940001133
日期:——
Incubations of (4R)- and (4S)-[4-2H1]-proclavaminic acid with clavaminic acid synthase resulted in the stereospecific removal of the deuterium and hydrogen respectively from C-4, in their conversions to clavaminic acid, suggesting an enzyme catalysed syn-eliminaion for the desaturation of dihydroclavaminic acid to clavaminic acid.
Experiments and speculations on the role of oxidative cyclization chemistry in natural product biosynthesis
作者:Craig A Townsend、Amit Basak
DOI:10.1016/s0040-4020(01)81792-0
日期:——
3′-2H2]proclavaminic acid, (22) and (29) respectively, are described. These labeled substrates were incubated with clavaminate synthase, a key enzyme acting in the biosynthesis of the lactamase inhibitor clavulanicacid, in the presence of ferrous ion, α-ketoglutaric acid and molecularoxygen. The apparent oxidative cyclization/desaturation chemistry evident in the conversion of proclavaminic acid (8) to clavaminic
A substrate analogue study on clavaminic acid synthase: possible clues to the biosynthetic origin of proclavamic acid
作者:Jack E. Baldwin、Matthew D. Lloyd、Byeng Wha-Son、Christopher J. Schofield、Stephen W. Elson、Keith H. Baggaleyb、Neville H. Nicholson
DOI:10.1039/c39930000500
日期:——
Incubation of (2S)-5-amino-(2′-oxoazetidin-1′-yl)pentanoic acid with clavaminic acid synthase gave (2S)-5-amino-2-(2′-oxoazetidin-1′-yl)pent-3,4-enoic acid as the major product, together with a small amount of proclayaminic acid; modification of the amino group to the guanyl group biased the mode of reactivity from desaturation to hydroxylation.
Isolation of an intermediate in clavulanic acid biosynthesis
作者:Jack E. Baldwin、Robert M. Adlington、Justin S. Bryans、Alain O. Bringhen、Janice B. Coates、Nicholas P. Crouch、Matthew D. Lloyd、Christopher J. Schofield、Stephen W. Elson、Keith H. Baggaley、Robert Cassells、Neville Nicholson
DOI:10.1039/c39900000617
日期:——
The operation of a primary isotope effect was utilised to enable a hitherto unknown intermediate in clavulanicacidbiosynthesis to be isolated and characterised.
利用主要同位素效应的操作,可以分离和表征棒酸生物合成中迄今未知的中间体。
Spectroscopic Studies of Substrate Interactions with Clavaminate Synthase 2, a Multifunctional α-KG-Dependent Non-Heme Iron Enzyme: Correlation with Mechanisms and Reactivities
作者:Jing Zhou、Wendy L. Kelly、Brian O. Bachmann、Michele Gunsior、Craig A. Townsend、Edward I. Solomon
DOI:10.1021/ja004025+
日期:2001.8.1
five-coordinate only when both substrate and alpha-KG are bound, the latter still in a bidentate mode. Absorption, CD, MCD, and VTVH MCD studies of the interaction of CS2 with DGPC, PC, and DPC provide significant molecular level insight into the structure/function correlations of this multifunctional enzyme. There are varying amounts of six-coordinate ferrous species in the substrate complexes, which correlate