BACKGROUND Lipase from Rhizopus chinensis is a versatile biocatalyst for various bioconversions and has been expressed at high-level in Pichia pastoris. However, the use of R. chinensis lipase in industrial applications is restricted by its low thermostability. Directed evolution has been proven to be a powerful and efficient protein engineering tool for improvement of biocatalysts. The present...

hly is a cDNA gene derived from human leukocytes that encodes a mature human lysozyme (abbreviated to hLY). The aim of the present study was to determine the effect of cloned hly on recombinant hLY (r-hLY) activity under optimized conditions. hly was amplified by RT-PCR and ligated into the pPIC9K plasmid. The cloned cDNA (hly) was 393 bp in length, encoding a 130 amino acid hLY with a calculat...

In Saccharomyces cerevisiae the activity for the lactate-proton symporter is dependent on JEN1 gene expression. Pichia pastoris was transformed with an integrative plasmid containing the JEN1 gene. After 24 h of methanol induction, Northern and Western blotting analyses indicated the expression of JEN1 in the transformants. Lactate permease activity was obtained in P. pastoris cells with a V (m...

To further improve the expression level of recombinant xylanase in Pichia pastoris, the xynB gene, encoding the mature peptide from Aspergillus niger NL-1, was designed and synthesized based on the synonymous condon bias of P. pastoris and optimized G+C content. 155 nucleotides were changed, and the GC content decreased from 57.7% to 43.6%. The synthetic xynB was inserted into the pPICZaA and t...

BACKGROUND Cellulosic biomass especially agricultural/wood residues can be utilized as feedstock to cost-effectively produce fuels, chemicals and bulk industrial enzymes, which demands xylose utilization from microbial cell factories. While previous works have made significant progress in improving microbial conversion of xylose into fuels and chemicals, no study has reported the engineering of...

Starved first instar Aedes aegypti larvae were 35-fold more sensitive to Bacillus thuringiensis subsp. israelensis (Bti) toxins than fed larvae. Feeding larvae Pichia pastoris yeast cells expressing tmfA (synthetic gene coding for the Trypsin Modulating Oostatic Factor of Ae. aegypti) together with Escherichia coli cells expressing Bti toxin genes (cry4Aa, cry11Aa, cyt1Aa and p20) indicate that...

Chinese hamster ovary (CHO) cells are currently the workhorse of the biopharmaceutical industry. However, yeasts such as Pichia pastoris are about to enter this field. To compare their capability for recombinant protein secretion, P. pastoris strains and CHO cell lines producing human serum albumin (HSA) and the 3D6 single chain Fv-Fc anti-HIV-1 antibody (3D6scFv-Fc) were cultivated in comparab...

A series of strategies were applied to improve expression level of recombinant endo-β-1,4-xylanase from Aspergillus usamii (A. usamii) in Pichia pastoris (P. pastoris). Firstly, the endo-β-1,4-xylanase (xynB) gene from A. usamii was optimized for P. pastoris and expressed in P. pastoris. The maximum xylanase activity of optimized (xynB-opt) gene was 33500 U/mL after methanol induction for 144 h...

Pichia pastoris is one of the most widely used expression systems for the secretory expression of recombinant proteins. The secretory expression in P. pastoris usually makes use of the prepro MATα sequence from Saccharomyces cerevisiae, which has a dibasic amino acid cleavage site at the end of the signal sequence. This is efficiently processed by Kex2 protease, resulting in the secretion of hi...

Background: Follicle stimulating hormone is a heterodimeric protein composed of two subunits, α and ß, which are linked noncovalently. The hypophysial gonadotropin FSH plays an important role in the regulation of oocyte maturation, and a key component for growth of ovulator follicles in ewes. Materials and Methods: This study seeks to clone and express the ovine follicle stimulating hormone sub...