SYNTHESIS AND TESTING OF HETEROCYCLIC-ANALOGS OF DIAMINOPIMELIC ACID (DAP) AS INHIBITORS OF DAP DEHYDROGENASE AND DAP EPIMERASE
SYNTHESIS AND TESTING OF HETEROCYCLIC-ANALOGS OF DIAMINOPIMELIC ACID (DAP) AS INHIBITORS OF DAP DEHYDROGENASE AND DAP EPIMERASE
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DOI：
10.1021/ja00094a004
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发表时间：
1994-07-27
影响因子：
15
通讯作者：
VEDERAS, JC
中科院分区：
文献类型：
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作者：
ABBOTT, SD;LANEBELL, P;VEDERAS, JC
合成了底物类似物，并对其作为球形芽孢杆菌二氨基戊酸（DAP）脱氢酶抑制剂和大肠杆菌DAP epimerase抑制剂进行了研究。这些酶分别从l -四氢二吡啶酸(1)和LL-DAP(2)产生中位磷酸二酶(3)（l -赖氨酸和肽聚糖的前体）。通过改进的方法纯化了epimase，并通过与DAP异构体、l -赖氨酸、d -赖氨酸、l - α -氨基苯甲酸酯和外消旋α -氨基苯甲酸酯进行氘交换实验，证实了该酶需要羧基和两个氨基来识别底物。以咪唑-4-羧酸苄酯(8)与n -苄基氧羰基(Cbz)- l-丝氨酸β -内酯(9)缩合为原料（x射线分析证实了产物结构），然后水解脱保护，合成了DAP的咪唑类类似物(2S)-2-氨基-3-（4-羧基咪唑-1-基）丙酸(4)。另外两种类似物(2S,5' r)-2-氨基-3-（3-羧基-2-异唑啉-5-基）丙酸(5)及其5' s非对映体6，由n- cbz - l -烯丙基甘氨酸甲酯（13）与氯肟酰乙酸甲酯（14）缩合，然后用NaOH和Me(3)SiCl/NaI分离异构体并进行脱保护。氯肟酰乙酸乙酯与乙烯缩合和14与丙烯酸乙酯缩合生成异恶唑啉，分别皂化为2-异恶唑啉-3-羧酸（25）和2-异恶唑啉-3,5-二羧酸（26）。除了6是一种有效的、特异性的DAP脱氢酶抑制剂外，这些化合物都没有表现出对DAP epimase或DAP脱氢酶的显著抑制作用。在pH 7.5或7.8时，化合物6与四氢二吡啶酸(1)对正向反应表现出竞争性抑制（K-i = 4.2 μ M），与中位磷酸二甲酯(3)对逆向反应表现出非竞争性抑制（K-i = 23 μ M）。初步抑菌活性试验表明，6能抑制球形芽孢杆菌的生长，而球形芽孢杆菌完全依靠DAP脱氢酶产生3。
Substrate analogues were synthesized and examined as inhibitors of diaminopimelic acid (DAP) dehydrogenase from Bacillus sphaericus and of DAP epimerase from Escherichia coli. These enzymes produce meso-DAP (3) (a precursor for L-lysine and for peptidoglycan) from L-tetrahydrodipicolinic acid (1) and LL-DAP (2), respectively. The epimerase was purified by an improved procedure and confirmed to require both carboxyl and both amino groups for substrate recognition using deuterium-exchange experiments with DAP isomers, L-lysine, D-lysine, L-alpha-aminopimelate, and racemic alpha-aminopimelate. An imidazole analogue of DAP, (2S)-2-amino-3-(4-carboxyimidazol-1-yl)propanoic acid (4), was synthesized by condensation of benzyl imidazole-4-carboxylate (8) with N-benzyloxycarbonyl(Cbz)-L-serine beta-lactone (9) (product structure confirmed by X-ray analysis) followed by hydrogenolytic deprotection. Two other analogues, (2S,5'R)-2-amino-3-(3-carboxy-2-isoxazolin-5-yl)propanoic acid (5) and its 5'S diastereomer 6, were prepared by condensation of methyl N-Cbz-L-allylglycinate (13) with methyl chlorooximidoacetate (14) followed by separation of isomers and deprotection with NaOH and Me(3)SiCl/NaI. Similar condensation of ethyl chlorooximidoacetate with ethylene and of 14 with ethyl acrylate generated isoxazolines, which were saponified to 2-isoxazoline-3-carboxylic acid (25) and 2-isoxazoline-3,5-dicarboxylic acid (26), respectively. None of the compounds show significant inhibition of DAP epimerase or DAP dehydrogenase with the exception of 6, which is a potent and specific inhibitor of DAP dehydrogenase. At pH 7.5 or 7.8, compound 6 shows competitive inhibition (K-i = 4.2 mu M) with tetrahydrodipicolinic acid (1) for the forward reaction and noncompetitive inhibition (K-i = 23 mu M) with meso-DAP (3) for the reverse process. Preliminary tests for antimicrobial activity demonstrate that 6 inhibits the growth of B. sphaericus, which relies exclusively on DAP dehydrogenase to produce 3.