Lo H H, Hsieh S E, Tsai K J, Chung J G
Department of Medical Technology, Chungtai Institute of Health Sciences and Technology, Taichung, Taiwan, ROC.
Drug Chem Toxicol. 1999 Aug;22(3):555-62. doi: 10.3109/01480549909042532.
Arylamine N-acetyltransferase (NAT) activity in Pseudomonas aeruginosa was inhibited by ellagic acid (EA), a naturally occurring dietary plant phenol. By measuring the acetylation of 2-aminofluorene (2-AF), the NAT activity was determined. In P. aeruginosa ATCC 27853, a NAT activity of 1.37 +/- 0.25 nmol/min/10(10) CFU for intact cell and a NAT activity of 5.92 +/- 0.20 nmol/min/mg protein for cytosolic preparation were measured. EA (ranging from 1 to 0.125 mM) showed a dose-dependent inhibition of NAT activities in the analysis of both intact cell and cytosolic preparations. Enzymatic kinetics were determined and found that EA was a potent non-competitive inhibitor of NAT activity in P. aeruginosa ATCC 27853. EA inhibition of NAT activities in P. aeruginosa ATCC 27853 was time-dependent for at least 4 hrs. These data strongly indicated that EA could suppress NAT activity in P. aeruginosa.
鞣花酸（EA）是一种天然存在的膳食植物酚，可抑制铜绿假单胞菌中的芳胺N-乙酰基转移酶（NAT）活性。通过测量2-氨基芴（2-AF）的乙酰化来测定NAT活性。在铜绿假单胞菌ATCC 27853中，完整细胞的NAT活性为1.37±0.25 nmol/分钟/10(10) CFU，胞质制备物的NAT活性为5.92±0.20 nmol/分钟/毫克蛋白质。在完整细胞和胞质制备物分析中，EA（浓度范围为1至0.125 mM）对NAT活性呈剂量依赖性抑制。测定了酶动力学，发现EA是铜绿假单胞菌ATCC 27853中NAT活性的有效非竞争性抑制剂。EA对铜绿假单胞菌ATCC 27853中NAT活性的抑制作用至少在4小时内呈时间依赖性。这些数据有力地表明，EA可抑制铜绿假单胞菌中的NAT活性。
