title: On a basic 31 kDa muscle membrane protein in cattle and pig, presumably equivalent to the class II antigen associated p31 molecule.
abstract: In a recent paper we gave evidence by two-dimensional electrophoresis that, in man, the class II antigen associated glycoprotein p31 (also called Ii, In, M1, DR gamma, XM1) is expressed not only in the membranes of B lymphocytes but also in those of muscle, liver and brain. It can therefore be assumed that the p31 is not really associated with the human class II antigens but is a ubiquitous molecule. Here we demonstrate for the first time that the muscle membranes of cattle and pig contain corresponding polypeptides, with a molecular weight of about 31 kDa and an isoelectric point around 7.5, which comigrate in two-dimensional electrophoresis with p31 derived from the human muscle. Thus, in cattle and pig too, these proteins seem to be equivalent to the class II antigen associated p31, showing a tissue distribution wider than observed up to now. The molecules can be concentrated by ion-exchange chromatography.
mesh_terms: D000818:Animals; D000941:Antigens / Q000302:isolation & purification; D002417:Cattle; D006684:HLA-DR Antigens; D006801:Humans; D007526:Isoelectric Point; D008562:Membrane Glycoproteins; D008565:Membrane Proteins / Q000276:immunology / Q000302:isolation & purification*; D008970:Molecular Weight; D009124:Muscle Proteins / Q000276:immunology / Q000302:isolation & purification*; D046988:Proteasome Endopeptidase Complex; D011506:Proteins / Q000276:immunology / Q000302:isolation & purification*; D013045:Species Specificity; D013552:Swine
chemical_list: D000941:Antigens; D006684:HLA-DR Antigens; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009124:Muscle Proteins; C501479:PSMD8 protein, human; D011506:Proteins; C035572:XM1 protein, human; D046988:Proteasome Endopeptidase Complex