Sevoflurane modulates the activity of glyceraldehyde 3-phosphate dehydrogenase

Abstract

The mechanism of inhalation anesthesia remains to be fully elucidated. While certain neuronal membrane proteins are considered sites of action, cytosolic proteins may also be targets. We hypothesize that inhaled anesthetics may act via glyceraldehyde 3-phosphate dehydrogenase (GAPDH), which has recently been shown to participate in neuronal inhibition. We examined the effects of sevoflurane, a halogenated ether anesthetic, on the catalytic and fluorescence properties of GAPDH. Initial rates of oxidoreductase activity decreased approximately 30% at saturating levels of sevoflurane. NADH-stimulated oxidoreductase activity (25 microM NADH; 0.8mM NAD+) increased with sevoflurane. Sevoflurane quenched tryptophan fluorescence emission and increased polarization. Additionally, sevoflurane increased the susceptibility of GAPDH to thermal denaturation suggesting an effect on conformation. Our findings warrant further research on sevoflurane's effect on GAPDH and indicate that this approach may lead to delineation of a novel contribution to the mechanism of anesthesia.

Isoflurane Enhances the Moonlighting Activity of GAPDH: Implications for GABAA Receptor Trafficking

“…We previously observed that sevoflurane inhibited the activity of GAPDH [4]. In this study, we also observed that isoflurane decreased the activity of GAPDH (Figure 1(a)) in the absence of ULVs.…”

“…GAPDH's binding to the cytoplasmic domain of the α-subunit of the GABA A receptor may be involved in the assembly and trafficking of the receptor. We previously demonstrated that volatile anesthetics affect GAPDH structure and function [3,4], findings that are consistent with those from other studies [5,6]. We propose that the binding of anesthetic agents to GAPDH may contribute to the effect of GAPDH on the GABA A receptor, particularly those involving membrane dynamics.…”

“…Enzyme activity was measured as described previously [4]. The reaction was monitored by an increase in 340 nm absorbance due to formation of NADH using D-glyceraldehyde (10 mM) as the substrate in a buffer containing 40 mM triethanolamine (pH 8.6), 50 mM sodium phosphate, 5 mM EDTA, 1 mM NAD + , and 20 mM D/L-glyceraldehyde.…”

“…We previously showed that volatile anesthetics affect GAPDH structure and function [3,4]. Sevoflurane, for example, alters the kinetic properties of GAPDH, and isoflurane affects the oligomeric configuration of the protein.…”

Interfacial Effects on the Conformation of Amyloid-Beta Peptide

“…We previously showed that inhaled anesthetics do not sequester proteins, separate from water and remain in liquid form on the bottom of the test vessel due to its density (1.52 g/cm 3 ) [15]. In the current study aqueous ABP was exposed to two interfaces, which we hypothesized may affect ABP conformation and aggregation.…”