| abstract |
A protein satisfying all the biological criteria characteristic of inhibin has been isolated from a gonadal source. The present invention describes the purification and characterization of inhibin and the use of the purified material to raise antibodies, the use of inhibin and said antisera in quantitative radioimmunoassay, as well as in vitro and in vivo inhibin and inhibin antibody. The present invention provides an inhibin, purified protein, characterized in that a) its apparent molecular weight determined by SDS-PAGE is 56,000 9E 1,000; b) its isoelectric point is between 6.9 and 7.3; c) this protein can specifically bind to concanavalin-A-sepharose; d) this protein is formed of two subunits, characterized in that i) their apparent molecular weights determined by SDS-PAGE are 44,000 9E 3,000 and 14,000 9E 2,000 respectively; ii) the isoelectric point of the 44,000 molecular weight subunit is between 6.0 and 7.0; iii) the N-terminal amino acid sequences of the two subunits are described in the present invention; e) this protein can suppress follicle stimulating hormone but not luteinizing hormone, thyroid stimulating hormone or prolactin in an in vitro biological analysis system; f) this protein can be labeled with radioactive iodine. Also provided is a method of isolating and purifying inhibin from the mammalian ovarian follicular fluid, characterized by a) one or more steps of gel penetration chromatography, b) one or more steps of reverse phase liquid chromatography of high yield, c) one or more steps of preparation polyacrylamide gel electrophoresis, d) electrophoretic elution of the purified inhibin. |