Open AccessMethyl Acceptors for Protein Methylase II from Human‐Erythrocyte Membrane
Author(s) -
GALLETTI Patrizia,
PAIK Woon Ki,
KIM Sangduk
Publication year - 1979
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1979.tb13106.x
Subject(s) - glycophorin , band 3 , biochemistry , methylation , membrane protein , methyltransferase , polyacrylamide gel electrophoresis , chemistry , membrane , gel electrophoresis , erythrocyte membrane , enzyme , biology , microbiology and biotechnology , dna
Membrane proteins from human erythrocytes were methylated with purified protein methylase II ( S ‐adenosylmethionine: protein‐carboxyl O ‐methyltransferase, EC.2.1.1.24). The methylated proteins were analyzed by dodecyl sulfate/polyacrylamide gel electrophoresis. Monomeric and dimeric glycophorin A (NaIO 4 /Schiff‐2 and NaIO 4 /Schiff‐1 positive bands) and ‘band 4.5’ were identified as two major classes of methyl‐acceptor polypeptides for protein methylase II. In rabbit erythrocyte membrane where glycophorin A is absent, ‘band 4.5’ was the only major methyl‐acceptor protein component. Extracted and purified glycophorin A from human erythrocytes was also found to be an excellent substrate for protein methylase II with a K m of 35.7 μM. The role of erythrocyte membrane protein methylation is discussed with regard to membrane function.