Effect of NAD coenzyme on the inactivation of glyceraldehyde‐3‐phosphate dehydrogenase by anionic phospholipids

Abstract

The inactivation of bovine heart glyceraldehyde-3-phosphate dehydrogenase by phosphatidylinositol (PI) and phosphatidylserine (PS) in the form of liposomes was investigated in the presence and absence of NAD excess. In the absence of NAD, the enzyme activity decreased to about ~0% of its initial value at 0.6 mM PI and 0.8 mM PS (lipid-to-protein molar ratio 600 and 800, respectively). In the same lipid concentration range almost full regainment of the activity was observed in the presence of 80/~M NAD. It was shown that the excess of NAD protects the enzyme against conformational change induced by the phospholipids. Centrifugation experiments showed that both PI and PS bind significant amounts of NAD.Glyceraldehyde-3-phosphate dehydrogenase; Phosphatidylinositol; Phosphatidylserine; Lipid-protein interaction

Identification of glyceraldehyde-3-phosphate dehydrogenase as a Ca2+-dependent fusogen in human neutrophil cytosol

“…Sidorowicz et al [27] found that interaction of rabbit muscle GAPDH with negatively charged phospholipids decreases enzymatic activity, and that nicotinamide adenine dinucleotide could protect GAPDH from inactivation by membrane phosphatidylinositol. Glaser et al [18] proposed that a GAPDH isoform isolated from rabbit brain cytosol could mediate Ca 2ϩ -independent fusion of complex liposomes constructed to resemble a biological membrane (PC 27%, PS 6%, cholesterol 40%, and plasmenylethanolamine 27%).…”