SEGREGATED CHARACTERIZATION OF RECOMBINANT EPOXIDE HYDROLASE SYNTHESIS VIA THE BACULOVIRUS-INSECT CELL EXPRESSION SYSTEM

The baculovirus/insect cell expression system has promise for the econ omic production of complex eucaryotic proteins for use as human or ani mal therapeutics. In this system, the polyhedrin gene of the Autograph a californica nuclear polyhedrosis virus (AcNPV) is replaced by the ge ne for a protein-of-interest. Spodoptera frugiperda cells, when infect ed with the recombinant baculovirus, express the desired protein after three days. In this work, a segregated model is presented that descri bes this system. The cell population consists of viable uninfected cel ls (X(VNI)), infected cells (X(I)), dead cells (X(D)), and total cells (X(T)) The viable infected cell population is further subdivided into cells producing virus, cells producing recombinant protein, and cells producing neither. The model is mathematically tractable, yet is suff iciently complex to describe the segregated nature of the infection pr ocess. Substrate limitations are included. Also, the model includes a decreasing specific glucose consumption rate after infection until lys is. Results suggest a metabolic-state-dependent virus infection effici ency, which has not been shown previously. Also, the glucose concentra tion during the protein production phase is found to be critical in su staining synthesis. Finally, secondary infections are successfully pre dicted, demonstrating that the model is useful in aiding the design an d optimization of large-scale systems where economic constraints are m ore prevalent.