Purification of the prothoracicotropic hormone from the tobacco hornworm |
| |
Authors: | Timothy G. Kingan |
| |
Affiliation: | Department of Biochemistry and Biophysics Oregon State University Corvallis, Oregon 97331, USA |
| |
Abstract: | Standard biochemical procedures were used to purify the prothoracicotropic hormone (PTTH) 4400 fold from whole head extracts of fifth instar larvae. Hormonal activity was bioassayed by injection into neck-ligated fourth instar larvae. The hormone was stable to heating at 85°C. Ammonium sulfate and acetone fractionation provided a crude preparation which showed dose-dependent activity in the bioassay. Chromatography on Sephadex G-100, DEAE-Sephadex, and hydroxylapatite gave a preparation with 2.6 PTTH units/μg protein (4400-fold purification). Activity was sensitive to proteolytic enzymes. Further purification by preparative electrophoresis gave a preparation which migrated as a single band in two polyacrylamide gel electrophoresis systems. A molecular weight estimate of 25,000 Daltons was obtained for this bands on SDS polyacrylamide gels. |
| |
Keywords: | Present Address Department of Biological Sciences Columbia University New York New York 10027 USA |
本文献已被 ScienceDirect 等数据库收录! |