title: Purification of heat shock protein 90 from calf uterus and rat liver and characterization of the highly hydrophobic region.
abstract: Heat shock protein 90 was purified from calf uterus and rat liver. Both heat shock protein 90s had similar molecular weights, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, of Mr 87,000 and 88,000, isoelectric points of 5.2, and Stokes radii of 6.7 and 6.5 nm, respectively. Heat shock protein 90 bound to phenyl-Sepharose CL-4B even at low ionic strength, and also bound to butyl-Toyopearl at high ionic strength. Heat shock protein 90 bound to phenyl-Sepharose could be eluted with a buffer containing organic solvents or detergents such as 2-propanol, dioxane, dimethylformamide, methyl cellosolve, 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate or Triton X-100, but not with ionic salts such as 1 M KCl. These results suggest that heat shock protein 90 possesses a significant hydrophobic region on the surface of the molecule. Hydrophobicities of heat shock protein 90 and 4S calf uterine estrogen receptor were both decreased by formation of a 8 S estrogen receptor complex. The role of the hydrophobic region of heat shock protein 90 in the interaction with estrogen receptor and other proteins is discussed.
authors.affiliation: Department of Biochemistry, Faculty of Science, Niigata University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Iwasaki
authors.forename: H
authors.initials: H
authors.lastname: Saito
authors.forename: M
authors.initials: M
authors.lastname: Yamamoto
authors.forename: K S
authors.initials: KS
authors.lastname: Korach
authors.forename: T
authors.initials: T
authors.lastname: Hirogome
authors.forename: H
authors.initials: H
authors.lastname: Sugano
mesh_terms: D000818:Animals; D002417:Cattle; D002850:Chromatography, Gel; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D006360:Heat-Shock Proteins / Q000302:isolation & purification*; D008099:Liver / Q000378:metabolism*; D011487:Protein Conformation; D051381:Rats; D011919:Rats, Inbred Strains; D011960:Receptors, Estrogen / Q000032:analysis; D014599:Uterus / Q000378:metabolism*
chemical_list: D006360:Heat-Shock Proteins; D011960:Receptors, Estrogen