Expression of Bovine β-Casein in Saccharomyces Cerevisiae and Characterization of the Protein Produced in Vivo
Published in Journal of Agricultural and Food Chemistry, Volume 38, Issue 4, April 1, 1990, pages 1134-1141.
NOTE: At the time of publication, the author Rafael Jiménez-Flores was affiliated with the University of California, Davis. Currently, May 2008, he is Professor of Dairy Science at California Polytechnic State University - San Luis Obispo, CA.
Recombinant DNA technology offers numerous opportunities for engineering food proteins and for studying their structure-function relationship. As part of the study of structure-function of bovine caseins, it is necessary to produce mutant proteins in experimental amounts and correlate their new structure to their physiochemical characteristics. To this end, bovine β-casein was expressed in the yeast Saccharomyces cerevisia by a fusion to the HXK1 (hexokinase P1) gene. Casein was produced during late exponential/early stationary phase of growth on glucose as would be predicted for a gene under the control of the HXK1 promoter. Bovine β-casein was posttranslationally modified by yeast. Internal phosphorylated forms were observed as well as a high molecular weight form that appeared to be O-glycosylated and largely localized to the periplasmic space.