ATP-DEPENDENT INACTIVATION AND SLOW BINDING-INHIBITION OF SALMONELLA-TYPHIMURIUM D-ALANINE-D-ALANINE LIGASE (ADP) BY (AMINOALKYL)PHOSPHINATE AND AMINOPHOSPHONATE ANALOGS OF D-ALANINE
ATP-DEPENDENT INACTIVATION AND SLOW BINDING-INHIBITION OF SALMONELLA-TYPHIMURIUM D-ALANINE-D-ALANINE LIGASE (ADP) BY (AMINOALKYL)PHOSPHINATE AND AMINOPHOSPHONATE ANALOGS OF D-ALANINE
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DOI：
10.1021/bi00410a028
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发表时间：
1988-05-17
期刊：
影响因子：
2.9
通讯作者：
WALSH, CT
中科院分区：
文献类型：
--
作者：
DUNCAN, K;WALSH, CT
在鼠伤寒沙门氏菌中，D-丙氨酸：D-丙氨酸连接酶（ADP）（EC 6.3.2.4）是肽聚糖生物合成的三酶D-丙氨酸分支途径中的第二个酶。已经研究了这种酶与可能的过渡态类似物（氨基烷基）次膦酸盐D-3-[（1-氨基乙基）氧膦基]-2-庚基丙酸的相互作用[Parsons等人（1987）Abstracts of Papers，193 rd National Meeting of the American Chemical Society，Denver，CO，MEDI 63，American Chemical Society，华盛顿，DC]。该化合物是有效的活性位点定向抑制剂，与D-丙氨酸竞争（Ki = 1.2 μ M）;在ATP存在下，它表现出时间依赖性抑制。动力学分析揭示了稳态抑制的快速开始（kon = 1.35 ×104 M-1 s-1），随后抑制复合物缓慢解离，半衰期为8.2 h。抑制复合物由E. cntdot组成。. cntdot. . cntdot. I. cntdot. . cntdot. . cntdot. ATP与E. cntdot平衡。. cntdot. . cntdot. I，Pi和ADP。用D-（1-氨乙基）膦酸（D-Ala-P）也观察到类似的时间依赖性抑制（Ki = 0.5 mM; kon = 27 M-1 s-1; t1/2 reain = 1.73 min），但用D-（1-氨乙基）次膦酸则没有，其表现为简单的竞争性抑制剂（Ki = 0.4 mM）。根据甲硫氨酸亚砜亚胺和膦丝菌素对谷氨酰胺合成酶的抑制先例，讨论了抑制机制。
In Salmonella typhimurium, D-alanine:D-alanine ligase (ADP) (EC 6.3.2.4) is the second enzyme in the three enzyme D-alanine branch pathway of peptidoglycan biosynthesis. The interaction of this enzyme with a possible transition-state analogue, the (aminoalkyl)phosphinate D-3-[(1-aminoethyl)phosphinyl]-2-heptylpropionic acid [Parsons et al. (1987) Abstracts of Papers, 193rd National Meeting of the American Chemical Society, Denver, CO, MEDI 63, American Chemical Society, Washington, DC], has been studied. This compound is a potent active site directed inhibitor and is competitive with D-alanine (Ki = 1.2 .mu.M); it exhibits time-dependent inhibition in the presence of ATP. Kinetic analysis revealed a rapid onset of steady-state inhibition (kon = 1.35 .times. 104 M-1 s-1) followed by slow dissociation of inhibitory complex(es) with a half-life of 8.2 h. The inhibitory complex was shown to consist of E .cntdot. .cntdot. .cntdot. I .cntdot. .cntdot. .cntdot. ATP in equilibrium with E .cntdot. .cntdot. .cntdot. I, Pi, and ADP. Similar time-dependent inhibition was also observed with D-(1-aminoethyl)phosphonic acid (D-Ala-P) (Ki = 0.5 mM; kon = 27 M-1 s-1; t1/2 for regain = 1.73 min) but not with D-(1-aminoethyl)phosphinic acid, which behaved as a simple competitive inhibitor (Ki = 0.4 mM). The mechanism of inhibition is discussed in the light of the precedents of glutamine synthase inhibition by methionine sulfoximine and phosphinothricin.