Molecular dynamics simulation and experimental study of the surface-display of SPA protein via Lpp-OmpA system for screening of IgG

Abstract

Staphylococcal protein A (SpA) is a major virulence factor of Staphylococcus aureus. S. aureus is able to escape detection by the immune system by the surface display of protein A. The SpA protein is broadly used to purify immunoglobulin G (IgG) antibodies. This study investigates the fusion ability of Lpp’-OmpA (46−159) to anchor and display five replicate domains of protein A with 295 residues length (SpA295) of S. aureus on the surface of Escherichia coli to develop a novel bioadsorbent.First, the binding between Lpp’-OmpA-SPA295 and IgGFc and the three-dimensional structure was investigated using molecular dynamics simulation. Then high IgG recovery from human serum by the surface-displayed system of Lpp’-OmpA-SPA295 performed experimentally. In silico analysiswas demonstrated the binding potential of SPA295 to IgG after expression on LPP-OmpA surface. Surface-engineered E. coli displaying SpA protein and IgG-binding assay with SDS-PAGE analysis exhibited high potential of the expressed complex on the E. coli surface for IgG capture from human serum which is applicable to conventional immune precipitation.

Non-covalent Linking Antibody to Yeast Using the Cell Surface Display of Staphylococcal Protein A

“…Kronqvist and colleagues have displayed the library of staphylococcal protein A (SpA)-derived affibody molecules on the surface of staphylococci and used the flow cytometry to isolate binders with subnanomolar apparent affinity for TNF-alpha successfully (Kronqvist et al, 2008). Vahed and colleagues experimental studied the surface display of SPA protein via Lpp-OmpA system for the screening of IgG (Vahed et al, 2020).…”