A new system for the bacterial expression of a variant of bovine alpha-lactalbumin has been developed. Eighteen mutant proteins containing single site substitutions in a cluster of predominantly aromatic residues adjacent to the cleft (aromatic cluster I) and in the hydrophobic box were expressed. The proteins were extracted from inclusion bodies and treated to generate native folding and disulfide bonds to provide appropriately folded protein samples for nine of the mutants. These were chara...