title: Co-production of GroELS discriminates between intrinsic and thermally-induced recombinant protein aggregation during substrate quality control.
abstract: BACKGROUND
  The effects and effectiveness of the chaperone pair GroELS on the yield and quality of recombinant polypeptides produced in Escherichia coli are matter of controversy, as the reported activities of this complex are not always consistent and eventually indicate undesired side effects. The divergence in the reported data could be due, at least partially, to different experimental conditions in independent research approaches.
  
  
  RESULTS
  We have then selected two structurally different model proteins (namely GFP and E. coli β-galactosidase) and two derived aggregation-prone fusions to explore, in a systematic way, the eventual effects of GroELS co-production on yield, solubility and conformational quality. Host cells were cultured at two alternative temperatures below the threshold at which thermal stress is expected to be triggered, to minimize the involvement of independent stress factors.
  
  
  CONCLUSIONS
  From the analysis of protein yield, solubility and biological activity of the four model proteins produced alone or along the chaperones, we conclude that GroELS impacts on yield and quality of aggregation-prone proteins with intrinsic determinants but not on thermally induced protein aggregation. No effective modifications of protein solubility have been observed, but significant stabilization of small (encapsulable) substrates and moderate chaperone-induced degradation of larger (excluded) polypeptides. These findings indicate that the activities of this chaperone pair in the context of actively producing recombinant bacteria discriminate between intrinsic and thermally-induced protein aggregation, and that the side effects of GroELS overproduction might be determined by substrate size.
authors: Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.
authors: Gemma
authors: G
authors: Platas
authors: Escarlata
authors: E
authors: Rodríguez-Carmona
authors: Elena
authors: E
authors: García-Fruitós
authors: Olivia
authors: O
authors: Cano-Garrido
authors: Antonio
authors: A
authors: Villaverde
mesh_terms: D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006358:Hot Temperature; D011487:Protein Conformation; D017510:Protein Folding; D001616:beta-Galactosidase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; C028715:GroE protein, E coli; D006360:Heat-Shock Proteins; D049452:Green Fluorescent Proteins; D001616:beta-Galactosidase