Effects of glucose on the production of recombinant protein C in mammalian cell culture

Abstract

Effects of glucose on a cultured Chinese hamster ovary cell line producing recombinant human protein C were investigated. After the recombinant cells reached confluency, they were maintained in the medium containing 10% serum and different levels of glucose in either batch or daily-exchange mode. High concentrations of glucose to the cultures yielded higher cell densities. Daily exchanges of media produced higher cell densities than the corresponding batch culture. Total protein C production per cell decreased with time in batch culture, in accordance with the declined glucose metabolism. Supplementation of the media with high levels of glucose diminished both the expression and gamma-carboxylation activities of the recombinant cells. Production of protein C persisted in daily-exchange culture, resulting in a constant production rate of protein C. In this case again, glucose reduced the specific productivity of recombinant protein C. An apparent glucose inhibition constant was determined to be 0.11 mg/mL by Dixon plots. The ability to gamma-carboxylate recombinant protein C was also impaired at the highest level of glucose. From these results, a strategy to maximize recombinant protein C productivity is discussed.

Properties of two insect cell lines useful for the baculovirus expression system in serum-free culture

“…The low toxic metabolite production of Sf9 cells has been noted in Excell medium and IPL-41 medium containing s e r~m .~~~,~~ Therefore, the less active metabolic production is characteristic of Sf9 cells grown in this series of media probably because of the highly efficient oxidative-phosphorylation pathway of the insect cells; which is quite different than that of mammalian cells. 18 The metabolism of Tn5 cells in Excell 401 medium appeared more similar to mammalian cell metabolism. It should be noted that, during both growth and infection phases, Tn5 cells showed a substantial consumption of sucrose, albeit at a delayed rate.…”

Structure-Activity Relationships of Bioengineered Heparin/Heparan Sulfates Produced in Different Bioreactors

“…The level of glucose in the culture medium has been reported to affect cell proliferation [ 32 ], as well as protein production and glycosylation [ 33 , 34 , 35 , 36 ]. A comparison of the results of this study and a previous study by the authors indicated that changes in the method of culture in tissue culture flasks is sufficient to alter both serglycin protein core production and the type of glycosaminoglycans [ 1 ].…”