Oka M, McCormick D B
J Biol Chem. 1987 May 25;262(15):7418-22.
Flavin adenine dinucleotide synthetase (ATP:FMN adenylyltransferase, EC 2.7.7.2) was purified about 10,000-fold from the high-speed supernatant of rat liver by a sequence of ammonium sulfate fractionation and column chromatographies on DEAE-Sephadex (A-50), chromatofocusing, FMN-agarose affinity, and Sephadex G-200. The specific activity of the purified enzyme was 133 units (nanomoles of FAD formed per min at 37 degrees C)/mg of protein. This preparation was free from contaminating FAD pyrophosphatase. The apparent molecular weight was estimated to be 97,000 by gel filtration on Sephadex G-200. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed an apparent subunit molecular weight of 53,000. Hence, the enzyme is a dimer of approximately 100,000. The enzyme was found most active at pH 7.1, requires Mg2+, and is essentially irreversible in the direction of FAD formation. Kinetic analysis gave Km values of 9.6 microM for FMN and 53 microM for ATP.
黄素腺嘌呤二核苷酸合成酶（ATP：FMN腺苷酰转移酶，EC 2.7.7.2）通过硫酸铵分级分离以及在DEAE - 葡聚糖（A - 50）上的柱色谱、聚焦层析、FMN - 琼脂糖亲和层析和葡聚糖G - 200从大鼠肝脏高速上清液中纯化了约10000倍。纯化酶的比活性为133单位（37℃下每分钟形成的FAD纳摩尔数）/毫克蛋白质。该制剂不含FAD焦磷酸酶污染物。通过在葡聚糖G - 200上的凝胶过滤，表观分子量估计为97000。十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳显示表观亚基分子量为53000。因此，该酶是一个约100000的二聚体。发现该酶在pH 7.1时活性最高，需要Mg2 +，并且在FAD形成方向上基本不可逆。动力学分析得出FMN的Km值为9.6 microM，ATP的Km值为53 microM。
