Purification and biochemical characterization of statin, a nonproliferation specific protein from rat liver.
The nuclear protein statin, detectable with specific monoclonal antibodies, is found mostly in nonproliferating cells (Wang, E. (1985) J. Cell Biol. 100, 545-551). In the rat liver a 57-kDa protein designated as rat liver protein 57 (RLp57) was recently identified to carry the epitope for the anti-statin-specific monoclonal antibody, S-44 (Sester, U., Moutsatsos, I. K., and Wang, E. (1989) Exp. Cell Res. 182, 550-558). To characterize further the RLp57 protein, in the present study a polyclonal antibody was raised to the RLp57 protein eluted from polyacrylamide gel. Similar to the anti-statin monoclonal antibody, this polyclonal antibody recognizes a nuclear antigen in nonproliferating fibroblasts and reacts with a 57-kDa protein in rat liver and nonproliferating cells strongly suggesting that RLp57 is a statin protein from rat liver. Two isoforms of RLp57 (isoelectric points between 6.5 and 7.0) were detected after two-dimensional gel electrophoresis and immunoblotting. RLp57 was purified using multiple chromatographic steps, including ion-exchange and affinity chromatography followed by chromatofocusing. These results show that RLp57, a statin protein found in liver, has two isoelectric variants and can be purified to apparent homogeneity by sequential steps of chromatographic procedures.
Sester
U
U
Bloomfield Centre for Research in Aging, Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Quebec, Canada.
Sawada
M
M
Wang
E
E
D000818:Animals; D000906:Antibodies / Q000276:immunology; D000918:Antibody Specificity; D015153:Blotting, Western; D018797:Cell Cycle Proteins; D002467:Cell Nucleus / Q000737:chemistry; D002845:Chromatography; D004591:Electrophoresis, Polyacrylamide Gel; D005455:Fluorescent Antibody Technique; D007525:Isoelectric Focusing; D007526:Isoelectric Point; D008099:Liver / Q000737:chemistry*; D008970:Molecular Weight; D009687:Nuclear Proteins; D011506:Proteins / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D051381:Rats; D011916:Rats, Inbred F344
D000906:Antibodies; D018797:Cell Cycle Proteins; D009687:Nuclear Proteins; D011506:Proteins