Chromaffin granule membrane glycoprotein IV is identical with Ac45, a membrane-integral subunit of the granule's H(+)-ATPase.
Glycoprotein IV of bovine adrenal chromaffin granule membranes was purified by membrane fractionation with Triton X-114 and lectin affinity chromatography. An antiserum raised against this protein recognized the same component as one directed against subunit Ac45 of the proton-translocating adenosine triphosphatase in the granule membrane. Amino acid sequencing confirmed that glycoprotein IV and Ac45 are identical proteins, and also showed that they are derived from a larger precursor by removal of a 246-amino acid N-terminal sequence. Enzymatic deglycosylation indicated an apparent polypeptide molecular mass of 29 kDa for the mature Ac45/glycoprotein IV. Blue Native electrophoresis confirmed that this protein is a component of the membrane sector of the V-ATPase.
Getlawi
F
F
Department of Biochemistry, University of Edinburgh, UK.
Laslop
A
A
Schägger
H
H
Ludwig
J
J
Haywood
J
J
Apps
D
D
D000313:Adrenal Medulla / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D019439:Chromaffin Cells / Q000378:metabolism*; D006023:Glycoproteins / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000378:metabolism*
D006023:Glycoproteins; D006180:Proton-Translocating ATPases