摘要

Rhizomucor miehei Lipase (RML) is widely used in the paper, food, cosmetics, pharmaceutical industries. In this study, nine potential endogenous signal peptide-like sequences with a secretory potential from Pichia pastoris were predicted by a SignalP 4.1 online software: FLO10, CPR5, PRY2, DSE4, NUP145, MSB2, SSP120, FRE2 and FLO9. Using the widely used α-mating factor (α-MF) signal peptide of Saccharomyces cerevisiae as the control, the effects of the nine endogenous signal peptides on the secretion of the enhanced green fluorescent protein (EGFP) and RML in a protease-deficient PichiaPinkTM expression system were investigated. The results showed that FLO10, PRY2, DSE4, MSB2, SSP120 and FRE2 could effectively mediate the secretion of EGFP. Moreover, the secretion level of EGFP mediated by PRY2, DSE4, MSB2 and FRE2 were 2.15, 1.15, 1.33, 1.30 folds, respectively, that of α-MF. FLO10, PRY2, DSE4 and FRE2 could effectively mediate RML secretion, with the highest secretion level of RML with FLO10 (which was 1.50 folds that of α-MF). This study laid a foundation for improving the expression of RML in protease-deficient Pichia pastoris.