Studies on pituitary follitropin. XII. Enhanced thermal stability induced by chemical deglycosylation

The receptor binding, immunological and biological activities of ovine follitropin were rapidly destroyed when aqueous solutions were kept in a boiling water bath. Similar treatment of the chemically deglycosylated follitropin (DG-FSH) showed less drastic effects on its hormonal properties. The latter preparation was more stable to heat treatment. A 30-min heat-treated DG-FSH was as active as native follitropin in the receptor-binding assay. Heat-treated DG-FSH solution still retained its capability to antagonize the action of native follitropin in the in vitro bioassay. The conformational features of deglycosylated follitropin required for receptor binding and immunological reactivity are preserved after heat treatment.