Characterization of a novel spermidine spermine acetyltransferase, BltD, from Bacillus subtilis
Characterization of a novel spermidine spermine acetyltransferase, BltD, from Bacillus subtilis
复制标题
DOI：
10.1042/0264-6021:3400753
复制
发表时间：
1999-06-15
影响因子：
4.1
通讯作者：
Gerner, EW
中科院分区：
文献类型：
--
作者：
Woolridge, DP;Martinez, JD;Gerner, EW
枯草芽孢杆菌中BltD基因的过表达导致多胺亚精胺和精胺的乙酰化。BltD与另一个基因Bit共调节，Bit编码多药物输出蛋白，其过表达促进亚精胺输出[Woolridge，Vazquez-Laslop，Markham，Chevalier，Gerner和Neyfakh（1997）J.Biol.Chem.272，8864-8866]。在这里，我们表明，BltD乙酰化亚精胺和精胺在伯丙胺部分，精胺是优选的底物。在存在饱和浓度的乙酰辅酶A的情况下，BltD在N-1和N-12位置处快速乙酰化精胺。精胺、亚精胺和N-1-乙酰精胺的Km（app）值分别小于或等于67、200和1200 μ M。从1，3-丙二胺到1，12-十二烷二胺、单乙酰腐胺和N-8-乙酰亚精胺都不是BltD的底物。腐胺（1，4-二氨基丁烷）和N-8-乙酰亚精胺是由BltD亚精胺乙酰化的竞争性抑制剂，Ki值分别为0.25和5.76 mM。辅酶A竞争性抑制亚精胺和乙酰辅酶A与BltD的相互作用。这些数据和其他结果表明，亚精胺和精胺乙酰化的机理是一个随机顺序的双分子动力学机制。
Overexpression of the BltD gene in Bacillus subtilis causes acetylation of the polyamines spermidine and spermine. BltD is co-regulated with another gene, Bit, which encodes a multidrug export protein whose overexpression facilitates spermidine export [Woolridge, Vazquez-Laslop, Markham, Chevalier, Gerner and Neyfakh (1997) J. Biol. Chem. 272, 8864-8866]. Here we show that BltD acetylates both spermidine and spermine at primary propyl amine moieties, with spermine being the preferred substrate. In the presence of saturating concentrations of acetyl CoA, BltD rapidly acetylates spermine at both the N-1 and N-12 positions. The K-m (app) values for spermine, spermidine and N-1-acetylspermine are less than or equal to 67, 200 and 1200 mu M, respectively. Diamines ranging from 1,3-diaminopropane to 1,12-diaminododecane, monoacetylputrescine and N-8-acetylspermidine were not substrates for BltD. Putrescine (1,4-diaminobutane) and N-8-acetylspermidine were competitive inhibitors of spermidine acetylation by BltD, with K-i values of 0.25 and 5.76 mM, respectively. CoA competitively inhibited both spermidine and acetyl-CoA interactions with BltD. These data and other results indicate that the mechanism of spermidine and spermine acetylation by BltD is a random-order mechanism of bi-molecular kinetics.