title: Latest approaches for efficient protein production in drug discovery.
abstract: BACKGROUND
  Pharmaceutical research looks to discover and develop new compounds which influence the function of disease-associated proteins or respective protein-protein interactions. Various scientific methods are available to discover those compounds, such as high-throughput screening of a library comprising chemical or natural compounds and computational rational drug design. The goal of these methods is to identify the seed compounds of future pharmaceuticals through the use of these technologies and laborious experiments. For every drug discovery effort made, the possession of accurate functional and structural information of the disease-associated proteins helps to assist drug development. Therefore, the investigation of the tertiary structure of disease-associated proteins and respective protein-protein interactions at the atomic level are of crucial importance for successful drug discovery.
  
  
  METHODS
  In this review article, the authors broadly outline current techniques utilized for recombinant protein production. In particular, the authors focus on bacterial expression systems using Escherichia coli as the living bioreactor.
  
  
  CONCLUSIONS
  The recently developed pCold-glutathione S-transferase (GST) system is one of the best systems for soluble protein expression in E. coli. Where the pCold-GST system does not succeed, it is preferable to change the host from E. coli to higher organisms such as yeast expression systems like Pichia pastoris and Kluyveromyces lactis. The selection of an appropriate expression system for each desired protein and the optimization of experimental conditions significantly contribute toward the successful outcome of any drug discovery study.
authors.affiliation: Osaka University, Institute for Protein Research , 3-2, Yamadaoka, Suita, Osaka 565-0871 , Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Sugiki
authors.forename: Toshimichi
authors.initials: T
authors.lastname: Fujiwara
authors.forename: Chojiro
authors.initials: C
authors.lastname: Kojima
mesh_terms: D000818:Animals; D061249:Batch Cell Culture Techniques; D002460:Cell Line; D055808:Drug Discovery / Q000379:methods*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005822:Genetic Vectors / Q000737:chemistry; D006801:Humans; D007716:Kluyveromyces / Q000235:genetics / Q000378:metabolism; D010843:Pichia / Q000235:genetics / Q000378:metabolism; D015202:Protein Engineering; D011994:Recombinant Proteins / Q000096:biosynthesis* / Q000235:genetics; D014162:Transfection
chemical_list: D011994:Recombinant Proteins
keywords: Escherichia coli; Fed-batch cultivation; high-cell-density cultivation; pCold-glutathione S-transferase system; protein expression system; single protein production system