Effects of methyl acetyl phosphate on hemoglobin S: a novel acetylating agent directed towards the DPG binding site.

Methyl acetyl phosphate (MAP) is an acetylating agent which prevents the polymerization of sickle cell hemoglobin (HbS). MAP can penetrate sickle erythrocytes and can acetylate intracellular HbS. Tryptic peptide mapping of modified HbS on reversed phase HPLC and amino acid analysis of isolated peptides revealed the acetylation sites to be Val-1 (beta), Lys-82 (beta), and Lys-144 (beta). MAP, therefore, is specifically directed towards the 2,3-DPG binding site of Hb.