鸡心辅酶Q-细胞色素c还原酶亲和层析分离及亚基拆分

本文证明鸡心线粒体辅酶Q-细胞色素c还原酶,于低离子强度下经Triton X-100增溶,亲和层析分离,得到单分散相的酶-Triton复合物。每微克分子酶含有低于0.15μmol辅酶Q以及12μmol的磷脂。还原态鸡酶的细胞色素b在α区表现两个吸收高峰,位于558,562nm;细胞色素c_1的α-吸收峰为553nm。SDS凝胶电泳指出,纯化的酶复合物至少由9个亚基组成。在高浓度盐和Triton X-100的作用下,酶复合物被解离为亚基复合物。三只氧化还原亚基(细胞色素b,c_1和Fe-S蛋白)被进一步分离、纯化。     

CHICKEN HEART UBIQUINOL:CYTOCHROME c REDUCTASE——ISOLATION BY AFFINITY CHROMATOGRAPHY AND RESOLUTION OF ENZYME INTO SUBUNITS

Chicken heart mitochondrial ubiquinol: cytochrome c reduetase has been isolated as a monodisperse form by solubilization with Triton X-100 in low ionic strength and subsequent affinity chromatography. The enzyme complex contains less than 0.15μmol ubiquinone and 12 μmol phospholipid per μmol enzyme. The spectrum of cytochreme b in the reduced enzyme exhibited two maximum α-absorption bands at 558nm and 562nm; a shoulder at 553 nm for c_1. The purified enzyme complex consists of at least 9 subunits with apparent molecular weight of 47K, 44K, 36K, 31K, 25K, 17K, 15K, 12K and 9K. The enzyme complex has been dissociated into subdomains of subunits in the presence of increasing concentration of salt and Triton X-100. Three subunits carrying the redox centers (cytochrome b, cytochrome c_1, and Fe-S protein) have been further isolated.     

QuEChERS提取-高效液相色谱法测定泰山虫草中4种黄曲霉毒素的含量

取泰山虫草样品2.50g,加入7.5mL水和含0.1%(体积分数)乙酸的乙腈混合溶液10mL,涡旋振荡1min,再加入无水硫酸镁4.0g和氯化钠1.0g,离心,取上清液1.0 mL于含150mg无水硫酸镁、50mg N-丙基乙二胺、50mg C18填料、12mg石墨化碳黑的2mL分散固相萃取管中,涡旋振荡30s,取上清液经过0.22μm有机滤膜进行过滤,采用高效液相色谱法测定其中4种黄曲霉毒素的含量。结果表明:4种黄曲霉毒素的质量浓度在一定范围内与其峰面积之间呈线性关系,检出限(3S/N)在0.06～0.20μg·kg-1之间。按照标准加入法进行加标回收试验,测得回收率在92.4%～102%之间,测定值的相对标准偏差(n=6)在2.7%～3.5%之间。