Electrochemical Studies of the Inhibition and Activation Effects of Al (III) on the Activity of Bovine Liver Glutamate Dehydrogenase

Abstract

Abstract:Since the study of Al 3+ ion on the enzyme activity by using of electrochemical techniques was rarely found in available literatures, the differential-pulse polarography (DPP) technique was applied to study the effects of Al At the plant and animal physiologically relevant pH values (pH=6.5 and 7.5), the GDH enzyme activities were strongly depended on the concentrations of the metal ion in the assay mixture solutions. In the lower Al (III) concentration solutions (<30 µM), the inhibitory effects were shown, which are in accordance with the recently biological findings. With the increase of Al (III) concentrations (30~80 µM), the enzyme GDH activities were activated. However, once the concentration of Al (III) arrived to near 0.1 mM level (>80µM), the inhibition effects of Al (III) were shown again. The cyclic voltammetry of NAD + and NAD + -GDH in the presence of Al (III) can help to explain some biological phenomena. According to the differential-pulse polarography and cyclic voltammetry experiments, the present research confirmed that the electrochemical technique is a convenient and reliable sensor for accurate determination of enzyme activity in biological and environmental samples.

Structural features of aluminium(III) complexes with bioligands in glutamate dehydrogenase reaction system – A review

“…Fig. 8 shows a well-defined differential pulse peak with the reduction potential of the NAD + at À0.86 V [7,36]. Meanwhile, a rather weak peak was at À0.97 V for a-KG.…”

“…This means that the GDH catalytical reaction started and finally arrived to the reversible equilibrium. It is showed that the differential pulse polarography technique could accurately determine the GDH activity in an enzymatic catalytical reaction [7].…”

“…Recently, we reported, at the plant and animal physiologically relevant pH values (pH 6.5 and 7.5), the activity of the GDH enzyme was strongly dependent on the concentration of the aluminium ion in the assayed mixture solutions [7]. Reduced GDH activity has also been reported in patients with Alzheimer's disease and Parkinson's disease [8].…”

Complexation of Al(III) with reduced glutathione in acidic aqueous solutions

“…In this study, the interactions between Al(III) and GSH were measured by multinuclear ( 1 H, 13 C, 27 Al) NMR and ESI-MS spectroscopy methods and pH-potentiometric titrations in acidic solutions. Like in natural amino acids, the carboxylate groups are effective binding sites for Al(III).…”

“…The results indicate that Al(III) has been found inside the cells in many illnesses [9]. It can bind to carboxylate, phosphate and other oxygen donating ligands of enzymes, coenzymes and substrates to form stable complexes [10][11][12][13][14][15]. By doing so, Al(III) may disrupt the enzyme activity in the mitochondria and thus affect the electron transport chain [16].…”