Dunlop P C, Meyer G M, Roon R J
J Biol Chem. 1980 Feb 25;255(4):1542-6.
Detailed kinetic analysis was performed on asparaginase II, a cell wall glycoprotein from Saccharomyces cerevisiae. The enzyme was highly active in the hydrolysis and hydroxylaminolysis reactions with D- and L-asparagine and with a variety of N-substituted analogues. The data from studies involving pH dependencey, substrate saturation, and product inhibition support the hypotheses that (a) the yeast asparaginase mechanism proceeds via an acyl enzyme intermediate; (b) an ionizable group on the enzyme, pK approximately 6.0, is involved in the acylation and deacylation reactions; and (c) yeast asparaginase II is a peptidoasparaginase.
对来自酿酒酵母的细胞壁糖蛋白天冬酰胺酶II进行了详细的动力学分析。该酶在与D-和L-天冬酰胺以及多种N-取代类似物的水解和羟胺分解反应中具有高活性。涉及pH依赖性、底物饱和以及产物抑制的研究数据支持以下假设:(a)酵母天冬酰胺酶机制通过酰基酶中间体进行;(b)酶上一个pK约为6.0的可电离基团参与酰化和脱酰化反应;以及(c)酵母天冬酰胺酶II是一种肽基天冬酰胺酶。