title: Large-scale purification of hnRNP proteins from HeLa cells by affinity chromatography on ssDNA-cellulose.
abstract: A purification procedure for proteins which bind heterogeneous nuclear RNA (hnRNP proteins) is described. The procedure, which entails standard chromatographic fractionations (single-stranded DNA cellulose, hydroxyapatite) and detection with specific antibodies, allows a large-scale preparation of these proteins and the partial separation of different polypeptides. By this method, polypeptides of higher molecular mass (53-55 kDa) can be purified, which are structurally and antigenically related to the 'canonical' hnRNP core proteins (34-43 kDa) that constitute the 40S hnRNP complexes. We also show that HeLa cells contain a protease that cleaves hnRNP core proteins to discrete smaller polypeptides of 22-28 kDa. Such protease, which has been partially purified, appears to copurify extensively with some of the hnRNP proteins.
mesh_terms: D002482:Cellulose / Q000031:analogs & derivatives; D002846:Chromatography, Affinity / Q000379:methods; D004247:DNA / Q000031:analogs & derivatives; D004277:DNA, Single-Stranded; D004591:Electrophoresis, Polyacrylamide Gel; D006367:HeLa Cells / Q000032:analysis; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006801:Humans; D006868:Hydrolysis; D010447:Peptide Hydrolases / Q000302:isolation & purification; D010455:Peptides / Q000302:isolation & purification; D012261:Ribonucleoproteins / Q000302:isolation & purification*; D014357:Trypsin
chemical_list: D004277:DNA, Single-Stranded; C033190:DNA-cellulose; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D010455:Peptides; D012261:Ribonucleoproteins; D002482:Cellulose; D004247:DNA; D010447:Peptide Hydrolases; D014357:Trypsin