Interaction of salmon gonadotropin subunits : spectroscopic studies

R. Salesse (1) , Josselin Garnier (1) , Bernard Breton (2)

1 Laboratoire de biochimie physique
2 Laboratoire de physiologie des poissons

Pituitary gonadotropins of female and male pacific salmon Oncorhynchus tshawytscha were prepared separately. The two preparations exhibited different sedimentationcoefficients (2.8 and 2.3, respectively) but similar circular dichroism spectra indicativeof low a helix and high β sheet contents. Both hormones gave a difference spectrum(1 750 M-1 cm-1m at 287 nm) characteristic of perturbed tyrosine and phenylalanine residues when dissociated at acid pH. These results suggest that fish and mammal gonadotropins exhibit the same general folding of their polypeptide chains and undergo the same conformation altransition when their subunits associate ; however, fish gonadotropin subunitsreassociate at considerably faster rates.

Mots clés: fish; salmonidae; oncorhynchus tshawytscha; salmon; gonadotropin; spectroscopy

Domaines: Biologie animale; Biochimie [q-bio.BM]; Biophysique

R. Salesse, Josselin Garnier, Bernard Breton. Interaction of salmon gonadotropin subunits : spectroscopic studies. Annales de biologie animale, biochimie, biophysique, 1978, 18 (4), pp.767-771. ⟨10.1051/rnd:19780502⟩. ⟨hal-00897344⟩