Production of a self-activating CBM-factor X fusion protein in a stable transformed Sf9 insect cell line using high cell density perfusion culture.

Factor Xa is a serine protease, whose high selectivity can be used to cleave protein tags from recombinant proteins. A fusion protein comprised of a self-activating form of factor X linked to a cellulose-binding module, saCBMFX, was produced in a stable transformed Sf9 insect cell line. The activity of the insect cell produced saCBMFX was higher than the equivalent mammalian cell produced material.

Effects of methanol concentration on expression levels of recombinant protein in fed-batch cultures of Pichia methanolica.

The methylotrophic yeast Pichia methanolica can be used to express recombinant genes at high levels under the control of the methanol-inducible alcohol oxidase (AUG1) promoter. Methanol concentrations during the induction phase directly affect cellular growth and protein yield. Various methanol concentrations controlled by an on-line monitoring and control system were investigated in mixed glucose/methanol fed-batch cultures of P.