Monoclonal antibody against an epitope on the cytoplasmic aspect of the plasma membrane calcium pump.
Monoclonal antibody PM4A2B was prepared by immunizing mice with calmodulin affinity purified Ca2+-Mg2+-adenosine triphosphatase from rabbit erythrocytes and screening the clones with a plasma membrane-enriched fraction (F1) from rabbit stomach smooth muscle. On Western blots, PM4A2B reacted with F1 and with ghosts, right-side-out vesicles, and inside-out vesicles prepared from erythrocytes giving one major band at 130 kDa and minor lower molecular weight bands whose intensity increased on freezing and thawing the membranes. On enzyme-linked immunosorbent assay, PM4A2B reacted with inside-out vesicles, but not with the right-side-out vesicles or ghosts prepared from erythrocytes. It activated the ATP-dependent Ca2+ uptake by F1 and by the inside-out vesicles prepared from the erythrocytes. PM4A2B should be useful in determining membrane sidedness as well as in investigating the mechanism of the sarcolemmal Ca2+ pump.
Grover
A K
AK
Department of Biomedical Sciences, McMaster University, Faculty of Health Sciences, Hamilton, Ontario, Canada.
D000818:Animals; D000911:Antibodies, Monoclonal; D017301:Ca(2+) Mg(2+)-ATPase / Q000097:blood* / Q000276:immunology; D000252:Calcium-Transporting ATPases / Q000097:blood* / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000032:analysis*; D004910:Erythrocyte Membrane / Q000201:enzymology*; D007700:Kinetics; D011817:Rabbits
D000911:Antibodies, Monoclonal; D000939:Epitopes; D017301:Ca(2+) Mg(2+)-ATPase; D000252:Calcium-Transporting ATPases