Ae. Fidler et al., Expression and secretion of a biologically active glycoprotein hormone, ovine follicle stimulating hormone, by Pichia Pastoris, J MOL ENDOC, 21(3), 1998, pp. 327-336
The methylotrophic yeast, Pichia pastoris, has been used to co-express reco
mbinant genes formed by fusion of the mating factor-alpha (MF alpha) leader
and ovine follicle stimulating hormone (oFSH) alpha and beta subunit codin
g sequences. Pichia strains carrying single copies of the two fusion genes
secreted recombinant oFSH (roFSH) to concentrations of approximately 51.0 n
g/ml and 17.5 ng/ml, measured by RIA or in vitro bioassay respectively, whe
reas a strain with two copies of the alpha and one copy of the beta subunit
fusion genes secreted roFSH to concentrations of 61 ng/ml (RIA) and 22 ng/
ml (bioassay). It appears that the Pichia-derived roFSH had about one-third
the in vitro bioactivity of native oFSH or, alternatively, only one-third
of the roFSH is bioactive. Measurements of secreted roFSH alpha and beta su
bunit concentrations indicated less than 10% of alpha and 25-33% af beta su
bunits were stably dimerized. The receptor binding properties of the roFSH
resemble those of native oFSH. In summary this paper reports the production
, by P. pastoris, of a heterodimeric glycoprotein hormone (roFSH) that has
in vitro biological activity.