A large percentage of protein products from genetically engineered cells exist in scrambled forms and are biologically nonfunctional. First, unfolding and then refolding these inactive products into active proteins is one of the most important problems of the new biotechnology. Hardly any bioprocess engineering research has ever been done in this area and, in fact, most engineers have not been aware of such difficulties until recently. This study will examine several related approaches to refold a model protein, xylose isomerase, after first unfolding. The objective is the development of bioprocessing techniques that will allow improved percentage yield of active products from scrambled proteins.
