Studies on a primary factor which stimulates DNA synthesis in isolated thymocytes: Part II--Bioassay, partial purification and characterization
Saxena, R.K.
Indian Journal of Biochemistry and Biophysics 15(6): 433-438
1978
ISSN/ISBN: 0301-1208 PMID: 753740 Document Number: 127175
Anterior pituitary thymocytes. The stimulatory response was proportional to the log of concentration of APE. Increase in the concentration of thymocytes in the assay medium resulted in a decrease in stimulatory response. Young rat thymocytes were stimulated to maximal extent by APE. Thymocytes derived from old rats were also stimulated but to a lesser extent. Partial purification of PF was achieved; This involved precipitation by acetone from the trichloroacetic acid-soluble fraction of sheep pituitary homogenates, followed by purification on Dowex-1 column and fractionation on Biogel P-2 gel filtration column. A total of 128-fold purification was achieved by these purification steps. Using the calibrated gel filtration column, a MW of about 500 daltons was found for the pituitary factor. An isoelectric pH of 7.9 for the pituitary factor was obtained by using Dowex-1 ion-exchange columns.