Evaluation of foreign gene codon optimization in yeast: expression of a mouse IG kappa chain.

We have optimized the codons in an immunoglobulin kappa chain gene to those preferred in the yeast Saccharomyces cerevisiae. The mutant and wild type kappa chain genes were each fused with a synthetic invertase signal peptide that also contained only yeast-preferred codons, and expressed in the F762 yeast strain. The use of yeast-preferred codons resulted in a more than 5-fold increase in the rate of synthesis and at least a 50-fold increase in the steady state level of protein.