Evidence that both Ca(2+)-ATPase and (Ca2+ + Mg2+)-ATPase activities in the plasma membrane-rich fraction from bovine parotid gland reside on the same enzyme molecule.
1. Evidence was obtained that activities of both low-affinity Ca(2+)-ATPase and high-affinity (Ca2+ + Mg2+)-ATPase in the plasma membrane-rich fraction from bovine parotid gland reside on the same enzyme. 2. Two solubilized ATPases were purified by four steps of HPLC; and both activities eluted at the same fractions from each column, and the specific activity ratio of the two enzymes at each step was constant. 3. By non-denaturing PAGE, the final preparation gave a single band for both protein staining and activity staining for the two ATPases; and the Ca(2+)-ATPase activity comigrated with that of (Ca2+ + Mg2+)-ATPase. 4. In SDS-PAGE, each activity staining for the ATPases also gave a single band, and both activities comigrated. 5. These findings suggest that Ca(2+)-ATPase and (Ca2+ + Mg2+)-ATPase are a single enzyme.
Matsukawa
R
R
Department of Biochemistry, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
Hayakawa
M
M
Araya
M
M
Imamura
T
T
Takiguchi
H
H
D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D002417:Cattle; D002462:Cell Membrane / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D010306:Parotid Gland / Q000201:enzymology* / Q000648:ultrastructure; D013347:Subcellular Fractions / Q000201:enzymology
D017301:Ca(2+) Mg(2+)-ATPase; D000252:Calcium-Transporting ATPases; D002118:Calcium