Binding Studies on the Neisseria Opa Protein Interaction with Human CEACAM Receptor
Han, Ji In, Harrison Undergraduate Research Award, University of Virginia
Columbus, Linda, Department of Chemistry, University of Virginia
Pathogenic Neisseria bacteria, which cause the diseases meningitis and increasingly antibiotic-resistant forms of gonorrhea, induce engulfment into diverse cell types by engaging their outer membrane opacity-associated (Opa) adhesin proteins with the host receptor, carcinoembryonic antigen-related cellular adhesion molecules (CEACAMs). A widely-studied class of CEACAM receptors, CEACAM1, is expressed in most immune cells, and interacts with Opa60, an Opa protein variant. In addition to recognizing Opa60, CEACAM1 binds itself homotypically. N-glycosylation of residues on the CEACAM1 IgV domain (nCEACAM1) has been shown to prevent homodimerization, which is necessary to study the Opa60-nCEACAM1 interaction in vitro. The Opa60 binding interaction with N-glycosylated nCEACAM1 was investigated in vitro using surface plasmon resonance (SPR) spectroscopy. Additionally, binding conditions were optimized in order to improve immobilized Opa60 liposome surface regeneration and to reduce non-specific binding (NSB) to the streptavidin (SA)-coated SPR sensor surface. Significant reduction of NSB was achieved with the addition of 1% BSA to flow buffer. Initial binding studies suggest that a 1:1 steady-state kinetics model describes the wild-type Opa60 and GlcNAc-nCEACAM1 interaction, compared to a limited response from the HV-less (HV-) Opa60 control.
BS (Bachelor of Science)
Surface Plasmon Resonance, CEACAM, Neisseria, Biochemistry
UVA Harrison Undergraduate Research AwardUVA Department of ChemistryUVA Ingrassia Research GrantNIH Grant R01 GB10204
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