Patent ID: 8987173
Filing Date: 2015-03-24
Classification: C07K,C12N

Abstract:
1. A method for screening for mutations in a target protein sequence that is prone to misfolding or aggregation in the cytoplasm that alter solubility and/or folding of said target protein in the cytoplasm, comprising: a) introducing one or more mutations into the nucleic acid sequence that encodes said target protein; b) expressing the mutant target protein as a fusion protein in a host cell, wherein said fusion protein comprises a Tat leader signal, the target protein that is prone to misfolding or aggregation in the cytoplasm, and a selectable marker, wherein said fusion protein comprising a Tat leader signal, the target protein, and a selectable marker is translocated from the cytoplasm across a biological membrane into the periplasm as a correctly folded fusion protein as a requirement to confer selectable activity upon expression of said fusion protein by said host cell; and c) correlating expression of selectable activity with correct folding of the target protein in the cytoplasm, wherein said target protein is an antibody or antibody fragment.