Shukla O P, Aisien S O, Bergmann B, Hellmund C, Walter R D
Division of Biochemistry, Central Drug Research Institute, Lucknow, India.
Parasitol Res. 1996;82(3):270-2. doi: 10.1007/s004360050110.
A cytosolic polyamine N-acetyltransferase that preferentially catalyzes the acetylation of spermidine in the N8-position was identified in the free-living pathogenic amoeba Acanthamoeba culbertsoni. In addition to spermidine, the enzyme also catalyzed the acetylation of spermine and putrescine with Michaelis constants (Km values) of 97, 12, and 10 microM, respectively. The Km value for acetylcoenzyme A (acetyl-CoA) was estimated to be 11 microM, whereas CoA had an inhibitory constant of 6 microM. The N-acetylase has a molecular mass of approximately 45 kDa. That the enzyme preferentially catalyzed the acetylation of spermidine at the N8-position, resulting in N8-acetylspermidine, the preferred substrate of the polyamine oxidase found in A. culbertsoni, indicates a role for the enzyme in the production of 1,3-diaminopropane, the major polyamine found in the Acanthamoeba.
在自由生活的致病性变形虫库氏棘阿米巴中鉴定出一种胞质多胺N - 乙酰转移酶，该酶优先催化亚精胺在N8位的乙酰化反应。除亚精胺外，该酶还催化精胺和腐胺的乙酰化反应，其米氏常数（Km值）分别为97、12和10微摩尔。乙酰辅酶A（acetyl-CoA）的Km值估计为11微摩尔，而辅酶A的抑制常数为6微摩尔。该N - 乙酰转移酶的分子量约为45 kDa。该酶优先催化亚精胺在N8位的乙酰化反应，生成N8 - 乙酰亚精胺，这是库氏棘阿米巴中发现的多胺氧化酶的首选底物，表明该酶在1,3 - 二氨基丙烷（棘阿米巴中主要的多胺）的产生中发挥作用。
