申请人:INDIAN INSTITUTE OF SCIENCE
公开号:US20030157513A1
公开(公告)日:2003-08-21
This invention describes novel catalytically active cytosolic enzymes for triacylglycerol biosynthesis from eukaryotic systems. The complex from oleaginous yeast was enzymatically characterized, and was found to contain lysophosphatidic acid acyltransferase, phosphatidic acid phosphatase, diacylglycerol acyltransferase, acyl-acyl carrier protein synthetase, superoxide dismutase and acyl carrier protein. The triacylglycerol biosynthetic machinery rapidly incorporates free fatty acids as well as fatty acyl-coenzyme A into triacylglycerol and its biosynthetic intermediates. Lysophosphatidic acid acyltransferase, phosphatidic acid phosphatase and diacylglycerol acyltransferase from the complex were microsequenced. Acyl carrier protein, superoxide dismutase and diacylglycerol acyltransferase genes were cloned and expressed in bacterial system. The soluble triacylglycerol biosynthetic enzymes (lysophosphatidic acid acyltransferase, phosphatidic acid phosphatase, diacylglycerol acyltransferase) in yeast, rat adipocytes and human hepatocyte cell-line (HepG2) exist in the cytosol either as free enzymes or as a multienzyme complex.
本发明描述了真核生物系统中用于三酰甘油生物合成的新型催化活性细胞膜酶。对来自油脂酵母的复合体进行了酶学鉴定,发现其中包含溶血磷脂酸酰基转移酶、磷脂酸磷酸酶、二酰甘油酰基转移酶、酰基载体蛋白合成酶、超氧化物歧化酶和酰基载体蛋白。三酰甘油生物合成机制可迅速将游离脂肪酸和脂肪酰辅酶 A 转化为三酰甘油及其生物合成中间体。对复合体中的溶血磷脂酸酰基转移酶、磷脂酸磷酸酶和二酰基甘油酰基转移酶进行了微测序。在细菌系统中克隆并表达了酰基载体蛋白、超氧化物歧化酶和二酰基甘油酰基转移酶基因。酵母、大鼠脂肪细胞和人类肝细胞系(HepG2)中的可溶性三酰甘油生物合成酶(溶血磷脂酸酰基转移酶、磷脂酸磷酸酶、二酰甘油酰基转移酶)以游离酶或多酶复合物的形式存在于细胞质中。