Calmodulin purification and quantitation from bovine mammary tissue.
Calmodulin, a multifunctional calcium binding protein, has been purified to apparent homogeneity from bovine lactating mammary tissue. Calmodulin was purified by heat treatment and sequential anion exchange and gel exclusion chromatographies. The molecular weight of the purified protein was estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be 18,000 daltons. The purified protein produced a 10-fold stimulation of the activity of partially purified bovine brain cyclic nucleotide phosphodiesterase in a calcium-dependent manner. This report details a method for the assay of biologically active calmodulin from lactating mammary tissue based on its stimulation of partially purified bovine brain phosphodiesterase. We report concentrations (microgram/g tissue, mg protein, mg deoxyribonucleic acid) of biologically active calmodulin in bovine mammary tissue.
D000818:Animals; D001921:Brain / Q000201:enzymology; D002148:Calmodulin-Binding Proteins; D002352:Carrier Proteins / Q000302:isolation & purification*; D002417:Cattle / Q000378:metabolism*; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D005260:Female; D008321:Mammary Glands, Animal / Q000032:analysis*
D002148:Calmodulin-Binding Proteins; D002352:Carrier Proteins