Effect of signal peptides on the expression of laccase in Pichia pastoris

Abstract:

Abstract:［Objective］Expression level of laccase POXA1c would be increased by screening effective signal peptide in Pichia pastoris． ［Methods］According to 2D-gel and profile of P． pastoris genome sequence，seven signal peptides from high secreted endogenous proteins of P． pastoris X-33 were chosen to evaluate their secreted ability by using POXA1c as reporter protein.［Results］ Compared with POXA1c’s native signal peptide，the signal peptide of repressible acid phosphatases PHO5 and lectin-like protein FLO10 showed 2. 5-fold and 2-fold increase of laccase activity．Furthermore，PHO5-αpro and FLO10-αpro were constructed by fusing signal peptide of PHO5 and FLO10 with pro-peptide of α-MF respectively．The laccase activity under the leading of FLO10-αpro and PHO5-αpro showed 3-fold and 3. 5- fold laccase activity higher than native signal peptide，and showed 20% and 40% increase compared with saccharomyces cerevisiae α-MF signal respectively．［Conclusion］Signal peptides from high secreted endogenous proteins of P．pastoris X-33 could be effectively used to lead laccase expression in P．pastoris. The activity of POXA1c under the leading of the PHO5-αpro signal peptide was 57.98 U/mL after high density fermentation.