Studies on the de novo biosynthesis of NAD in Escherichia coli. V. Properties of the quinolinic acid synthetase system.
Studies on the de novo biosynthesis of NAD in Escherichia coli. V. Properties of the quinolinic acid synthetase system.
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大肠杆菌中NAD从头生物合成的研究。
DOI：
10.1016/0304-4165(73)90249-3
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发表时间：
1973
期刊：
影响因子：
--
通讯作者：
R. Gholson
中科院分区：
文献类型：
--
作者：
N. Suzuki;J. Carlson;G. Griffith;R. Gholson
大肠杆菌喹啉酸合成酶系统被分解为两个部分纯化的可溶性蛋白组分，一个来自anadA，另一个来自anadB突变体，底物天冬氨酸和磷酸二羟丙酮，以及辅因子FAD。用凝胶过滤法测定的表观分子量，从thenadB突变体获得的酶为35000，从thenadA突变体制备的酶为85000。在该系统中，天冬氨酸和磷酸二羟丙酮的表观Km值分别约为0.3和0.2 mM。喹啉酸合成的最适pH为8-8.5。
The quinolinic acid synthetase system ofEscherichia colihas been resolved into the following components: Two partially purified soluble protein fractions, one prepared from anadA and the other from anadB mutant; the substrates, aspartic acid and dihydroxyacetone phosphate and the cofactor FAD. The apparent molecular weights, as determined by gel filtration are 35 000 for the enzyme obtained from thenadB mutant and 85 000 for the enzyme prepared from thenadA mutant. The apparentKmvalues for aspartate and dihydroxyacetone phosphate in this system are about 0.3 and 0.2 mM, respectively. The pH optimum for quinolinic acid synthesis is 8–8.5.