Khachatrian G E, Simonian A L
Biokhimiia. 1988 Aug;53(8):1256-64.
Isolation and purification of L-lysine-2- monooxygenase from the bacterium Pseudomonas species was carried out. The purification procedure included ammonium sulfate fractionation, acid treatment, gel filtration through Sephadex G-200 and ion-exchange chromatography on DEAE-Sephadex A-50. Such treatment resulted in more than 220-fold purification and 22% yield; the specific activity of the enzyme is 14.6 U/mg. The enzyme spectrum is typical for flavoproteins, with peaks at 275, 386 and 462 nm. At 460 nm excitation, the enzyme fluorescence has an emission maximum at 530 nm, whereas at 360 nm extication--at about 520 nm. The molecular mass of L-lysine-2-monooxygenase as determined by SDS/PAAG electrophoresis is about 268 kD. The KM values for oxygen and lysine are equal to 6.5.10(-4) M and 2.3.10(-4) M, respectively. The curve for the dependence of the reaction rate on lysine concentration is sigmoidal. It was assumed that the electrophoretic behaviour of the enzyme confirms the hypothesis on the nature of allosteric regulation of the enzyme activity by alterations in the regulatory site charge.
从假单胞菌属细菌中分离纯化了L-赖氨酸-2-单加氧酶。纯化过程包括硫酸铵分级分离、酸处理、通过Sephadex G-200进行凝胶过滤以及在DEAE-Sephadex A-50上进行离子交换色谱。这样的处理导致了超过220倍的纯化和22%的产率;该酶的比活性为14.6 U/mg。该酶的光谱是黄素蛋白的典型光谱,在275、386和462 nm处有峰值。在460 nm激发下,该酶的荧光在530 nm处有最大发射峰,而在360 nm激发下——在约520 nm处。通过SDS/PAAG电泳测定的L-赖氨酸-2-单加氧酶的分子量约为268 kD。氧气和赖氨酸的KM值分别等于6.5×10⁻⁴ M和2.3×10⁻⁴ M。反应速率对赖氨酸浓度的依赖性曲线呈S形。据推测,该酶的电泳行为证实了关于通过调节位点电荷变化对酶活性进行变构调节性质的假设。