Open AccessStructural Relation of Two S‐100 Proteins in Bovine Brain; Subunit Composition of S‐100 a Protein
Author(s) -
ISOBE Toshiaki,
ISHIOKA Noriaki,
OKUYAMA Tsuneo
Publication year - 1981
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1981.tb06225.x
Subject(s) - protein subunit , sephadex , dimer , chemistry , gel electrophoresis , biochemistry , polyacrylamide gel electrophoresis , enzyme , gene , organic chemistry
Dodecyl sulfate/urea/polyacrylamide gel electrophoresis of S‐100a protein, one of the two major components of the brain‐specific S‐100 protein, indicated the presence of two different subunits in the protein. These subunits (α and β subunits) were purified from the aminoethylated protein by column chromatography on Sephadex G‐75, and the purified subunits were subjected to analyses. The results have shown that S‐100a protein is a dimer of α and β subunits, with each subunit having a molecular weight of approximately 10500. Structural comparison of these subunits with the subunit of S‐100b protein, the other component of S‐100 protein consisting of two identical subunits with known amino acid sequence, has revealed that the β subunit and the subunit of S‐100b protein are identical, so that S‐100a protein is related to S‐100b protein by sharing one of the subunits as a common structural constituent.