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Expression of Recombinant Proteins in the Methylotrophic Yeast Pichia pastoris
Published on: February 25, 2010
Expression and Purification of Functionally Active Recombinant Human Alpha 1-Antitrypsin in Methylotrophic Yeast
Sareh Arjmand1, Elham Bidram, Abbas Sahebghadam Lotfi
1Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran ; National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran ; School of Pharmacy, Zanjan University of Medical Science, Zanjan, Iran.
Abstract:
Human alpha 1-antitrypsin (AAT) cDNA was obtained from HepG2 cell lines. After PCR and construction of expression vector pPICZα-AAT, human AAT was expressed in the yeast Pichia pastoris (P.pastoris) in a secretary manner and under the control of inducible alcohol oxidase 1 (AOX1) promoter. The amount of AAT protein in medium was measured as 60 mg/l 72 hr after induction with methanol. Results indicated the presence of protease inhibitory function of the protein against elastase. Purification was done using His-tag affinity chromatography. Due to the different patterns of glycosylation in yeast and human, the recombinant AAT showed different SDS-PAGE patterns compared to that of serum-derived AAT while pI shifted from 4.9 in native AAT compared to 5.2 in recombinant AAT constructed in this study.
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