Carbamylated hemoglobin

Effective comparison of patterns of proteins on lEF/PAGE gels requires some method of normalizing the protein patterns to compensate for distortions in the patterns due to gel-to-gel variation in the analytical conditions in either the first- and/or second-dimension separation. Internal standards are valuable in monitoring variation in analytical conditions Isoelectric point standards for lEF based on carbamylated hemoglobin, fluorescein-labeled-hemoglobin, and creatine phospho-kinase (All, M5) can be prepared, as can molecular weight standards based on heart muscle proteins (G8). 

C rb myl tion. Modification of the amino-terminal groups of hemoglobin (Hb) by the carbamylation reaction using isocyanic acid [75-13-8]... 

J. M. Manning, ia E. Antonini, L. Rossi-Bemardi, and E. Chiancone, eds.. Methods in En mology, Hemoglobins, Academic Press, New York, 1981, pp. 159—167. Preparation of hemoglobin carbamylated at specific NH -terminal residues. 

Val 1-NAl, Lys 82-EF6, and His 143-H21) and deoxy Hb-S does not produce configuration changes which influence the aggregation of the molecules (B35). Moreover, cyanate (HN=C=0) which carbamylates amino terminal residues of proteins (R—NH—CO—NH2) is an effective inhibitor of sickling of erythrocytes in vitro and of gelling of concentrated solutions of deoxyhemoglobin S (C9). Addition of some specific hemoglobin variants, Hb-O-Arab or 02 2 (M16) and Hb-Korle Bu... 

Oimoni, M., Glycosylated haemoglobin in renal failure. Diabetologia 21, 163 (1981). Oimoni, M., Lshikawa, K., Kawasaki, T, Kubota, S., Yoshimura, Y, and Baba, S., Carbamylation of hemoglobin in renal failure and clinical aspects. Metabolism 33, 999-1002 (1984). 

Different proteins have been carbamylated to be used as charge standards. Carbamylated beta chains of hemoglobin (38) were reported to be stable standards, while Fawcett (39) took the approach of acetylation of myoglobin to produce charge standards for isoelectric focusing. Building on these standards, Tollaksen et al. 

When cyanate is administered to animals, most of the radioactivity is accounted for by carbamylation of NH2-terminal residues of hemoglobin. No detectable carbamylation of lysine or cystine residues is observed. The exact mechanism by which cyanate protects against sickling is not known. Because cyanate... 

Lippincott J, Apostol I. Carbamylation of cysteine a potential artifact in peptide mapping of hemoglobins in the presence of urea. Anal Bioehem. 1999 267 57-64. doi 10.1006/abio. 1998.2970. 

---