The Expression of Soluble and Active RecombinantHaemophilus influenzaeIgA1 Protease inE. coli

Abstract

Immunoglobulin A1 (IgA1) proteases fromHaemophilus influenzaeare extracellular proteases that specifically cleave the hinge region of human IgA1, the predominant class of immunoglobulin present on mucosal membranes. The IgA1 proteases may have the potential to cleave IgA1 complexes in the kidney and be a therapeutic agent for IgA1 nephropathy (IgAN), a disease characterized by deposition of the IgA1 antibody in the glomerulus. We have screened for the expression of recombinantH. influenzaeIgA1 protease by combining various expression plasmids, IgA1 protease constructs, andE. colistrains under multiple conditions. Using the method we have developed, approximately 20–40 mg/L of soluble and activeH. influenzaeIgA1 protease can be produced fromE. colistrain C41(DE3), a significant increase in yield compared to the yield upon expression inH. influenzaeor other related bacteria.