Effect of red cell membrane binding on the catalytic activity of glyceraldehyde-3-phosphate dehydrogenase

Abstract

Band 3, the anion transport protein of the human erythrocyte, provides the site of association of certain glycolytic enzymes with the membrane. We have now demonstrated that glyceraldehyde-3-P dehydrogenase is inhibited, reversibly and completely, when membrane bound. The inhibition was competitive with respect to NAD+ and arsenate, but was noncompetitive with glyceraldehyde-3-P. Peptide fragments containing the NH2-terminal 23 residues of band 3 also inhibited the enzyme and displaced it from ghosts. Thus, the red cell membrane binding site for glyceraldehyde-3-P dehydrogenase is the same as that for aldolase, the polyanionic NH2-terminal region of the band 3 polypeptide.