PLASMODIUM-KNOWLESI - PARTIAL-PURIFICATION AND CHARACTERIZATION OF NADP-GLUTAMATE DEHYDROGENASE

被引：0

作者：

WATTS, R ^{[1
]}

CHANDRA, D ^{[1
]}

KAUSHAL, NA ^{[1
]}

KAUSHAL, DC ^{[1
]}

机构：

[1] CENT DRUG RES INST,DIV MICROBIOL,LUCKNOW 226001,UTTAR PRADESH,INDIA

来源：

JOURNAL OF PROTOZOOLOGY RESEARCH | 1994年 / 4卷 / 01期

关键词：

PLASMODIUM-KNOWLESI; GLUTAMATE DEHYDROGENASE; MALARIAL PARASITE;

D O I：

暂无

中图分类号：

R38 [医学寄生虫学]; Q [生物科学];

学科分类号：

07 ; 0710 ; 09 ; 100103 ;

摘要：

An NADP-linked glutamate dehydrogenase (L-Glutamate dehydrogenase NADP-oxidoreductase, EC 1.4.1.4.) was purified 181 folds from Plasmodium knowlesi (simian malaria parasite) by ammonium sulfate fractionation, gel filtration and hydroxylapatite column chromatography. The molecular weight of the enzyme was found to be 295,000 as determined by gel filtration. The enzyme appeared to be heat stable (4 h at 56-degrees-C) and activated about 39% and 14% by KCl and NaCl respectively. It catalysed the amination of is-proportional-to-ketoglutarate and the deamination of glutamate with optimum activity at pH 7.4 and 8.6 respectively. Hyperbolic kinetics were observed for the substrates and cofactors yielding Km values of 0.25 +/- 0.02mM for is-proportional-to-ketogultrate, 1.3 +/- 0.2mM for ammonium acetate, 0.011 +/- 0.001mM for NADPH, 1.8+/-0.1mM for glutamate and 0.050+/-0.002 mM for NADP. The amination reaction was about 10 times more active as compared to the deamination reaction. Purine nucleotides did not show any effect on enzyme activity. These results suggest that the amination reaction may predominate in P.knowlesi parasites.

引用

页码：18 / 28

页数：11