Reinvestigation of extremely acidic proteins in bovine brain.
Analysis of bovine brain extract by disc electrophoresis on a 20% polyacrylamide gel indicated the existence of three extremely acidic proteins. These proteins were isolated by column chromatography on DEAE-Sephadex A-50 and Sephadex G-75. The isolated proteins (PAP I-a, PAP I-b and PAP II) were homogeneous in various methods including 7.5% and 20% gel electrophoresis or gel chromatography, and share, in the extract, 85% of the total of the acidic proteins that migrate with the bromophenol blue marker in 7.5% gels. Their physicochemical properties, including molecular weight, ultraviolet absorption spectra or amino acid composition were similar, especially those between PAP I-a and PAP I-b where a part of primary structure appeared to be common in their tryptic peptide maps. These two proteins were identified to be the nervous system specific protein S 100 by immunochemical and electrophoresis methods as well as by amino acid analysis, and the other protein PAP II was revealed to be a calcium-binding protein. The existence and properties of the isolated proteins are discussed with relation to the heterogeneity problem of S 100 protein.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001923:Brain Chemistry; D002417:Cattle; D002852:Chromatography, Ion Exchange; D003429:Cross Reactions; D004589:Electrophoresis, Disc; D004591:Electrophoresis, Polyacrylamide Gel; D007526:Isoelectric Point; D008970:Molecular Weight; D009419:Nerve Tissue Proteins / Q000032:analysis*; D010455:Peptides / Q000032:analysis; D009418:S100 Proteins / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification; D013056:Spectrophotometry, Ultraviolet; D014357:Trypsin
D000596:Amino Acids; D009419:Nerve Tissue Proteins; D010455:Peptides; D009418:S100 Proteins; D014357:Trypsin