Han Qian, Li Jianyong
Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 South Lincoln Avenue, Urbana, IL 61802, USA.
FEBS Lett. 2002 Sep 11;527(1-3):199-204. doi: 10.1016/s0014-5793(02)03229-5.
This study describes the comparative analysis of two insect recombinant aminotransferases, Aedes aegypti 3-hydroxykynurenine (3-HK) transaminase/alanine glyoxylate aminotransferase (Ae-HKT/AGT) and Drosophila melanogaster serine pyruvate aminotransferase (Dm-Spat), which share 52% identity in their amino acid sequences. Both enzymes showed AGT activity. In addition, Ae-HKT/AGT is also able to catalyze the transamination of 3-HK or kynurenine with glyoxylate, pyruvate or oxaloacetate as the amino acceptor. Kinetic analysis and other data suggest that Ae-HKT/AGT plays a critical role in mosquito tryptophan catabolism by detoxifying 3-HK and that Dm-Spat is primarily involved in glyoxylate detoxification.
本研究描述了两种昆虫重组氨基转移酶的比较分析,即埃及伊蚊3-羟基犬尿氨酸(3-HK)转氨酶/丙氨酸乙醛酸转氨酶(Ae-HKT/AGT)和黑腹果蝇丝氨酸丙酮酸转氨酶(Dm-Spat),它们的氨基酸序列有52%的同源性。两种酶均表现出AGT活性。此外,Ae-HKT/AGT还能够催化以乙醛酸、丙酮酸或草酰乙酸作为氨基受体时3-HK或犬尿氨酸的转氨作用。动力学分析和其他数据表明,Ae-HKT/AGT通过解毒3-HK在蚊子色氨酸分解代谢中起关键作用,而Dm-Spat主要参与乙醛酸解毒。