Record Display for the EPA National Library Catalog


Main Title Purification and Biological Characterization of Human Hepatopoietin A: A Polypeptide Growth Factor for Hepatocytes.
Author Zarnegar, R. ; Michalopoulos., M. ;
CORP Author Duke Univ. Medical Center, Durham, NC. Dept. of Pathology. ;National Institutes of Health, Bethesda, MD.;Health Effects Research Lab., Research Triangle Park, NC.
Publisher c1989
Year Published 1989
Report Number EPA-R-814344; EPA/600/J-89/469;
Stock Number PB91-115980
Additional Subjects Proteins ; Purification ; Liver ; Rats ; Reprints ; Hepatoprotein A ; Growth substances ; Cultured cells ; Polyacrylamide gel electrophoresis ; High pressure liquid chromatography ; Isoelectric focusing
Library Call Number Additional Info Location Last
NTIS  PB91-115980 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 9p
The presence of a high molecular weight polypeptide growth factor in the plasma of normal human or rat serum which stimulates DNA synthesis in primary cultures of normal rat hepatocytes has previously been reported. This activity was referred to as Hepatopoietin A (HPTA). At that time, however, complete purification of this growth factor had not been achieved. In the present report the steps required for complete purification of HPTA from human plasma or rabbit serum are described. The purification involved sequential ammonium sulfate precipitation, heparin-affinity chromatography, anion exchange HPLC, and reverse-phase HPLC. The final purified product is a heterodimer consisting of a heavy and a light polypeptide chain with M.W. of 70,000 and 35,000 respectively as determined by SDS-PAGE under reducing conditions. Under non-reducing conditions, however, the purified HPTA migrated as a single band on SDS-PAGE corresponding to a M.W. of 69,000. The mitogenic activity of HPTA was associated with this band when it was eluted from unstained SDS-polyacrylamide gels. Gel filtration HPLC under neutral isotonic conditions indicated that HPTA tends to form aggregates with M.W. of greater than 300,000. Chromatofocusing indicated that HPTA is an acidic protein with a PI of about 5.5.