The 48 kDa Ca2+-binding protein of bovine brain.
A Ca2+-binding protein of molecular mass 48 kDa and named 'CAB-48' has been purified from bovine brain 100,000 g supernatant. About 30 mg of CAB-48 was purified from 1 kg of bovine brain. The protein has been characterized with respect to its physical, chemical and Ca2+-binding properties. It has an apparent molecular mass of 48 kDa by SDS/polyacrylamide-gel-electrophoresis and 75.2 kDa from sedimentation-velocity and Stokes-radius data. The acidic nature of the molecule is suggested by its pI of 4.7. In the presence of 3.0 mM-MgCl2 and 150 mM-KCl, CAB-48 binds 1.0 mol of Ca2+/mol of protein with an apparent Kd of 15 microM. A tyrosine protein kinase partially purified from rat spleen catalysed the incorporation of 0.73 mol of phosphate/mol of CAB-48, and phosphoamino acid analysis revealed that phosphorylation of CAB-48 was specific for tyrosine residues.
Tokuda
M
M
Department of Medical Biochemistry, University of Calgary, Alberta, Canada.
Khanna
N C
NC
Waisman
D M
DM
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001923:Brain Chemistry; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000302:isolation & purification* / Q000378:metabolism; D002417:Cattle; D002848:Chromatography, DEAE-Cellulose; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D008970:Molecular Weight; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism
D000596:Amino Acids; D002135:Calcium-Binding Proteins; C043697:calcium-binding protein (brain); D011505:Protein-Tyrosine Kinases; D002118:Calcium