Comparison of Signal Peptides for Two Hemicellulase Secretory Expression / 中国生物工程杂志

ABSTRACT

Xylanase and mannanase are two hemicellulases,which are widely used in many fields.To improve the expression of thermostable xylanase DSB and thermostable mannanase ManA in Pichia pastoris,three endogenous signal peptides of Pichia pastoris(Scw1 1,Dse4 and Exg1) were chosed.Their capability to mediate the secretion of DSB and ManA with that of the Saccharomyces cerevisiae α-factor were compared.In shake-flask cultivation,three endogenous signal peptides and α-factor efficiently mediated the secretion of DSB and ManA,but the secretion efficiency has obvious difference.As for DSB,the expression efficiency of α-factor was much higher than three endogenous signal peptides.But as for ManA,the expression efficiency of Dse4 was equal to α-factor and much higher than Scw11 and Exg1.Therefore,α-factoris the most efficient signal peptide for DSB expression and Dse4 or α-factor are the most efficient signal peptide for ManA expression in Pichia pastoris X33.Moreover,the intracellular activities of DSB and ManA by α-factor are higher than Scw1 1,Dse4 and Exg1,and the intracellular activity of ManA was higher than DSB (the molecular weight of ManA was larger than DSB).Thus,when ManA were expressed in Pichia pastoris,different signal peptide,such as Dse4,could be used for improving the secretion efficiency.A basis for identifying more available signal peptides and screening for the optimal signal peptide for the target protein was provided.