Protein solubility

From DrugPedia: A Wikipedia for Drug discovery

The solubility of proteins in aqueous buffers depends on the distribution of hydrophilic and hydrophobic amino acid residues on the protein’s surface. Hydrophobic residues predominantly occur in the globular protein core, but some exist in patches on the surface. Proteins that have high hydrophobic amino acid content on the surface have low solubility in an aqueous solvent. Charged and polar surface residues interact with ionic groups in the solvent and increase solubility. Protein moleculaes are least souble at their isoelectric point, and solubility is dependent on sequence, so every protein is different. In bacterial system, recombinant proteins usually accumulate in the cytoplasm, and examples where recombinant protein constitutes up to 30 percent of total cellular protein can be found in the literature. However, excessive production is not without drawbacks, as the recombinant protein will sometimes misfold and aggregate into so-called inclusion bodies. ([1]). No universal approach has been established for the efficient folding of aggregation prone recombinant proteins (2). There are number of methods in literature for the redirection of proteins from inclusion bodies into the soluble cytoplasmic fraction. such as protein expression at reduced temperatures, different bacterial strains used to improve soluble expression, molecular chaperones drive folding of recombinant,Interaction partners and Fusion protein technology (GST or MBP fusion protein)

References

1. Sørensen HP, Mortensen KK: Advanced genetic strategies for recombinant expression in Escherichia coli. J Biotechnol 2005, 115:113-128.