乙酰乳酸合成酶的制备、分离与纯化

Preparation ,Separation and Purification of acetolactate Synthase

乙酰乳酸合成酶［１］（ａｃｅｔｏｌａｃｔａｔｅｓｙｎｔｈａｓｅ，ＡＬＳ）是目前国际上除草剂研究的前沿热点．它能催化一分子丙酮酸脱羧并与另一分子丙酮酸缩合成一分子乙酰乳酸，从而导致侧链氨基酸缬氨酸、亮氨酸和异亮氨酸的生物合成．存在于细菌和植物组织中［２...

Acetolactate synthase (ALS) is one of the lyase.It catalyzes the condensation of two molecules of pyruvate to form α acetolactate leading to the biosynthesis of branched amino acids valine,leucine and isoleucine. Separation,purification and storage of ALS from bacteria and plant tissue have been severely hampered by its intrinsic lability no homogeneity and low abundance.The pure enzyme and partly purified enzyme of ALS are the products in short supply on both domestic and foreign markets.The fine technological process of preparation ,separation and purification of ALS from dark grown pea shoots has been reported.In the optimal phosphate buffer solution,pyruvate was selected as natural substrates.Thiamine pyrophosphate,flavin adenine dinucleotide and magnesium choride were chosen as cofactors.Storage time of ALS obtained by the method was up to 30 days,half life times was 7_8 days and specific activity reached 223 μmol·L -1 ·mg -1 .The ALS has been used as target site for screening model.