Solubis: optimizing protein solubility by minimal point mutations

Abstract

Protein solubility is adapted to endogeneous protein abundance in the cell where protein folding is also assisted by multiple chaperones. During recombinant protein production, purification and storage proteins are frequently handled at concentrations that are several orders of magnitude above their physiological concentration, often resulting in protein aggregation. Here we describe SolubiS, a method allowing for (1) detection of aggregation prone linear segments within a protein sequence and (2) identification of mutations that abolish the aggregation propensity of these segments without affecting the thermodynamic stability of the protein. Provided the availability of structural information this method is applicable to all globular proteins including antibodies, resulting both in increased in vitro protein solubility and in better protein production yields.