| Popis: |
With the new knowledge generated through the Human Genome Project and related biomedical research comes a potential revolution in drug development strategies. One of the most direct applications of this knowledge will be highly specialized recombinant protein-based therapeutics. Recombinant drugs such as human erythropoietin (EPO), tissue plasminogen activator (tPA), and CerezymeTM (glucocerebrosidase) are currently on the market and many other recombinant proteins are in various stages of human clinical trials. Commercial production of these proteins utilizes fermentation (primarily E. coli and yeast) and mammalian cell systems (e.g., Chinese hamster ovary cells), the major expression systems adopted by the well established biotechnology companies. However, these expression systems have significant limitations. Bacteria cannot perform the complex posttranslational modifications required for bioactivity of many human proteins and high-level expression often leads to accumulation of insoluble protein aggregates. While mammalian cell cultures perform the required protein modifications, low transgene expression levels, instability of selected cell lines, and the difficulties and high expense of scale-up are often limiting or severely impact cost. Thus, there remains significant opportunity for alternative expression systems that address these limitations and cost issues to compete in the protein therapeutics market. In fact, development of more cost-effective protein bioproduction systems may be critical in translating the discoveries of genomics and medical research into widely available and affordable treatments and cures. |
