Proteomic analysis of Pichia pastoris a yeast highly used as a protein expression system

Abstract

Methylotrophic yeast, Pichia pastoris, is a widely used host for recombinant protein expression as it is easy to genetically manipulate and has rapid respiratory growth. Recently, a new strain capable of human-type N-glycosylation has been developed which increases its importance in biopharmaceuticals. A number of proteins such as insulin, human serum albumin, interferon-alpha as well as hepatitis B vaccine have been produced in P. pastoris. On the other hand different drug therapeutics such as monoclonal antibodies, fusion proteins are in the clinical investigation pipeline. The genome of GS115 strain of P. pastoris was sequenced few years ago with the prediction of 5,040 protein coding genes. This accelerated the research to characterize newer strains for improved protein production as well as to study the physiological characteristics under various physiological conditions. It is also used as a model organism for peroxisome biogenesis and methanol assimilation. Although, P. pastoris is used as a superior recombinant protein expression system mainly for mass production, there have been very few reports that describe the proteome of the P. pastoris. In order to characterize the proteome of P. pastoris, we utilized high-resolution Fourier transform mass spectrometry approach. Present study was carried out with the following objectives 1) In depth mass spectrometry-based proteomic analysis of P. pastoris, and 2) Genome annotation of P. pastoris using proteogenomic approach newline