ADENOSINE TRIPHOSPHATE-DEPENDENT CARBAMOYLPHOSPHATE-3-HYDROXYMETHYLCEPHEM ORTHO-CARBAMOYLTRANSFERASE FROM STREPTOMYCES-CLAVULIGERUS
ADENOSINE TRIPHOSPHATE-DEPENDENT CARBAMOYLPHOSPHATE-3-HYDROXYMETHYLCEPHEM ORTHO-CARBAMOYLTRANSFERASE FROM STREPTOMYCES-CLAVULIGERUS
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DOI：
10.1042/bj1850555
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发表时间：
1980-01-01
影响因子：
4.1
通讯作者：
TURNER, MK
中科院分区：
文献类型：
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作者：
BREWER, SJ;TAYLOR, PM;TURNER, MK
从S. clavuligerus（N.R.R.L.）3585），其活性合成头孢霉素C，将氨基甲酰基从氨基甲酰基磷酸转移到3-羟甲基头孢-3-烯-4-羧酸核上，形成3-氨基甲酰基氧基甲基头孢烯。该反应由核苷三磷酸和由Mn 2+和Mg 2+阳离子的混合物刺激。负责的酶纯化40倍，通过批量吸附到DEAE-纤维素和羟基磷灰石。纯化的O-氨基甲酰基转移酶在pH 6.8时最具活性。它被磷酸根阴离子稳定，但被PPi阴离子、（NH 4）2SO 4或NaCl抑制。这种酶受ATP刺激，但不知道这种核苷酸是作为效应物还是作为底物。用dATP观察到一些活性，但用2种其它ATP类似物观察到一些活性，其中亚甲基取代了α-ATP之间的O2原子。和β-或β-和γ- P原子，抑制ATP本身的作用。该酶可合成多种3-氨基甲酰氧基甲基头孢烯。这些产物中的一些的结构，例如头孢呋辛{3-氨基甲酰氧基甲基-7 β- [2-（呋喃-2-基）-2-顺式-甲氧亚氨基乙酰胺基]头孢-3-烯-4-羧酸}的结构经核磁共振氢谱确证。
Cell-free supernatants from cells of S. clavuligerus (N.R.R.L. 3585), which are actively synthesizing cephamycin C, transfer a carbamoyl group from carbamoylphosphate to a 3-hydroxymethylceph-3-em-4-carboxylic acid nucleus to form a 3-carbamoyloxymethylcephem. This reaction was stimulated by nucleoside triphosphates and by a mixture of Mn2+ and Mg2+ cations. The enzyme responsible was purified 40-fold by batch absorption onto DEAE-cellulose and hydroxylapatite. The purified O-carbamoyltransferase is most active at pH 6.8. It is stabilized by phosphate anions, but is inhibited by PPi anions, (NH4)2SO4 or NaCl. The enzyme is stimulated by ATP, but it is not known whether this nucleotide acts as an effector or as a substrate. Some activity is observed with dATP, but 2 other analogs of ATP, in which a methylene group replaced the O2 atom between the .alpha.- and .beta.- or the .beta.- and .gamma.-P atoms, inhibit the action of ATP itself. The enzyme synthesizes a wide range of 3-carbamoyloxymethylcephems. The structure of some of these products, for example that of cefuroxime {3-carbamoyloxymethyl-7.beta.-[2-(fur-2-yl)-2-syn-methoxyiminoacetamido]ceph-3-em-4-carboxylic acid}, was confirmed by their proton-NMR spectra.