title: Studies on the effects of Al(III) on the lactate dehydrogenase activity by differential pulse voltammetry.
abstract: In this paper, differential-pulse voltammetry (DPV) was applied to study the effects of aluminum (Al(III)) on the lactate dehydrogenase (LDH) activity, K(m)(NADH) and nu(max) in the enzyme promoting catalytic reaction of "Pyruvate+NADH+H(+)right arrow over left arrowLDHLactate+NAD(+)" by monitoring DPV reduction current of NAD(+). The changes of Al's influence on the LDH activities caused by the concentration of LDH, pH, temperature as well as Al speciation including Al hydroxide (Al-OH), Al fluoride (Al-F) and organically complexing Al (Al-Org) compounds have been investigated. The results showed that the effects of Al on the LDH activity exhibited two kinds of behaviors under different conditions, i.e. inhibitory effects or slightly increased LDH activity at low concentrations and inhibited at high concentrations. To analyze the values of K(m)(NADH) and nu(max) of LDH reaction system in the absence and presence of 0.04mmol/L Al(III), it was found that the types of the inhibition of Al(III) varied with experimental conditions. The comparisons of effects of Al(III) with Pb(II), Cd(II) and Cr(III) on the LDH activities were also inspected.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China; Key Laboratory of MOE for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Kaian
authors.initials: K
authors.lastname: Yao
authors.forename: Na
authors.initials: N
authors.lastname: Wang
authors.forename: Jingyue
authors.initials: J
authors.lastname: Zhuang
authors.forename: Zhengbiao
authors.initials: Z
authors.lastname: Yang
authors.forename: Haiyan
authors.initials: H
authors.lastname: Ni
authors.forename: Quan
authors.initials: Q
authors.lastname: Xu
authors.forename: Cheng
authors.initials: C
authors.lastname: Sun
authors.forename: Shuping
authors.initials: S
authors.lastname: Bi