Oxidative modification of glyceraldehyde-3-phosphate dehydrogenase influences its interaction with endogenous neuroprotector isatin

Abstract

Glyceraldehyde 3 phosphate dehydrogenase (GAPDH), a classical glycolytic redox sensitive enzyme, exhibits various non glycolytic functions, which are considered to be especially important for pro gression of various neurodegenerative diseases. GAPDH binds isatin (indole dione 2,3), an endogenous indole often used as a parent component in numerous derivatives demonstrating diverse pharmacological (including neuroprotector) activities. In this study we have investigated binding of intact and mildly oxidized GAPDH to immobilized isatin, using an optical biosensor technique, employing surface plasmon resonance (SPR), and the effect of isatin as a probe for this binding. Mild GAPDH oxidation by 70 µM H 2 O 2 increased enzyme dissociation from immobilized isatin. Since GAPDH is considered as a putative target for various neuroprotector agents, this suggests that its redox state determines sensitivity to neuroprotective agents, and oxidative stress typical for various neurodegenerative disorders may significantly reduce pharmacological effectiveness of such compounds.

Isatin, an endogenous nonpeptide biofactor: A review of its molecular targets, mechanisms of actions, and their biomedical implications

“…Besides structural features of isatin derivatives, used as the affinity ligands (5‐amino‐isatin, 5‐aminocaproyl‐isatin), the redox state of the protein target appears to have a significant impact on its interaction with isatin. In the case of GAPDH, a classical glycolytic redox sensitive enzyme (exhibiting various nonglycolytic functions, important for progression of various neurodegenerative diseases) mild oxidation significantly increased its dissociation from the immobilized isatin analogue (Table ). This suggests that redox state(s) and possibly other types of posttranslational modifications regulate affinity of target proteins to isatin.…”

Mechanism of the Affinity-Enhancing Effect of Isatin on Human Ferrochelatase and Adrenodoxin Reductase Complex Formation: Implication for Protein Interactome Regulation

“…These numerous biological and/or pharmacological effects are obviously mediated by isatin interaction with many isatin-binding proteins, identified during proteomic profiling of brain preparations of mice and rats [ 3 , 4 , 5 ]. However, besides direct action of isatin on its particular targets, characterized by classical binding constants and altered biological functioning of individual proteins [ 6 , 7 ] it can also act as a bidirectional regulator of protein–protein interactions (PPI) increasing or decreasing affinity of interacting protein partners [ 1 , 8 ]. This novel regulatory role of isatin has been originally demonstrated by us for the interaction of two pairs of proteins: (1) ferrochelatase (FECH) and adrenodoxin reductase (ADR) [ 8 ], (2) thromboxane synthase (TBXAS1) and cytochrome P450 2E1 (CYP2E1) [ 9 ].…”