Effect of molecular chaperones on the expression of Candida antarctica lipase B in Pichia pastoris.

One of the reasons for limited heterologous protein secretion in Pichia pastoris is the suboptimal folding conditions inside the cell. The Hsp70 and Hsp40 chaperone families in the cytoplasm or the ER regulate the folding and secretion of heterologous proteins. Here, we have studied the effect of chaperones Ydj1p, Ssa1p, Sec63p and Kar2p on the secretory expression of Candida antarctica lipase B (CalB) protein.

Improved secretion of Candida antarctica lipase B with its native signal peptide in Pichia pastoris.

Secretion efficiency of the 85-amino acid Sacchromyces cerevisiae alpha signal peptide and the 25-amino acid Candida antarctica lipase B signal (nsB) peptide were compared. Three reporter proteins used for the study are C. antarctica lipase A (CalA), lipase B (CalB) and hGMCSF.