Residue Gln-30 of human erythrocyte anion transporter is a prime site for reaction with intrinsic transglutaminase.
Elevating the intracellular concentration of Ca2+ ions in human erythrocytes leads to the formation of membrane-associated polymers, composed of skeletal and cytoplasmic proteins. The anion transporter band 3 serves as a membrane anchor for this N epsilon-(gamma-glutamyl)lysine cross-linked polymer. The reaction is catalyzed by an intrinsic transglutaminase, and it can be observed in broken cells merely by the addition of Ca2+. Certain primary amines, such as dansylcadaverine, inhibit the process by virtue of competition against the epsilon-lysyl or donor functionalities of the protein substrates. Dansylcadaverine itself becomes incorporated into the enzyme-specific gamma-glutaminyl or acceptor residues, blocking these from participating in the formation of protein-to-protein cross-links. This labeling procedure, coupled with an anti-dansyl antibody affinity procedure to isolate dansyl-labeled compounds, was employed to identify Gln-30 as the preferred transglutaminase-reactive acceptor site in the band 3 protein.
Murthy
S N
SN
Department of Cell and Molecular Biology, Northwestern University Medical School, Chicago, Illinois 60611-3008.
Wilson
J
J
Zhang
Y
Y
Lorand
L
L
D000596:Amino Acids / Q000032:analysis; D001457:Anion Exchange Protein 1, Erythrocyte / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D002103:Cadaverine / Q000031:analogs & derivatives; D002118:Calcium / Q000494:pharmacology; D002846:Chromatography, Affinity; D002851:Chromatography, High Pressure Liquid; D004151:Dipeptides / Q000097:blood; D004591:Electrophoresis, Polyacrylamide Gel; D004910:Erythrocyte Membrane / Q000378:metabolism*; D005973:Glutamine; D006801:Humans; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification; D011503:Transglutaminases / Q000378:metabolism*
D000596:Amino Acids; D001457:Anion Exchange Protein 1, Erythrocyte; D004151:Dipeptides; D010446:Peptide Fragments; D005973:Glutamine; C001299:epsilon-(gamma-glutamyl)-lysine; D011503:Transglutaminases; C008542:monodansylcadaverine; D002103:Cadaverine; D002118:Calcium