title: Solubility of recombinant Src homology 2 domains expressed in E. coli can be predicted by TANGO.
abstract: BACKGROUND
  Signalling proteins often contain several well defined and conserved protein domains. Structural analyses of such domains by nuclear magnetic spectroscopy or X-ray crystallography may greatly inform the function of proteins. A limiting step is often the production of sufficient amounts of the recombinant protein. However, there is no particular way to predict whether a protein will be soluble when expressed in E.coli. Here we report our experience with expression of a Src homology 2 (SH2) domain.
  
  
  RESULTS
  The SH2 domain of the SH2D2A protein (or T cell specific adapter protein, TSAd) forms insoluble aggregates when expressed as various GST-fusion proteins in Escherichia coli (E. coli). Alteration of the flanking sequences, or growth temperature influenced expression and solubility of TSAd-SH2, however overall yield of soluble protein remained low. The algorithm TANGO, which predicts amyloid fibril formation in eukaryotic cells, identified a hydrophobic sequence within the TSAd-SH2 domain with high propensity for beta-aggregation. Mutation to the corresponding amino acids of the related HSH2- (or ALX) SH2 domain increased the yield of soluble TSAd-SH2 domains. High beta-aggregation values predicted by TANGO correlated with low solubility of recombinant SH2 domains as reported in the literature.
  
  
  CONCLUSIONS
  Solubility of recombinant proteins expressed in E.coli can be predicted by TANGO, an algorithm developed to determine the aggregation propensity of peptides. Targeted mutations representing corresponding amino acids in similar protein domains may increase solubility of recombinant proteins.
authors.forename: Thorny Cecilie Bie
authors.initials: TC
authors.lastname: Andersen
authors.forename: Kjersti
authors.initials: K
authors.lastname: Lindsjø
authors.forename: Cecilie Dahl
authors.initials: CD
authors.lastname: Hem
authors.forename: Lise
authors.initials: L
authors.lastname: Koll
authors.forename: Per Eugen
authors.initials: PE
authors.lastname: Kristiansen
authors.forename: Lars
authors.initials: L
authors.lastname: Skjeldal
authors.forename: Amy H
authors.initials: AH
authors.lastname: Andreotti
authors.affiliation: Department of Anatomy, Institute of Basal Medical Sciences, University of Oslo, Oslo, Norway. anne.spurkland@medisin.uio.no.
authors.forename: Anne
authors.initials: A
authors.lastname: Spurkland
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry*; D000465:Algorithms; D000595:Amino Acid Sequence; D002352:Carrier Proteins; D004926:Escherichia coli / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D015202:Protein Engineering; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D012995:Solubility; D018909:src Homology Domains
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; C442142:HSH2D protein, human; D047908:Intracellular Signaling Peptides and Proteins; D011993:Recombinant Fusion Proteins; C405691:SH2D2A protein, human; C492466:SH2D2A protein, rat; C402726:Sh2d2a protein, mouse