4Z3T

Meningococcal Factor H binding protein mutant L130R/G133D

Summary for 4Z3T

• Entry DOI: 10.2210/pdb4z3t/pdb
• Descriptor: Factor H binding protein variant A10_001, MAGNESIUM ION (3 entities in total)
• Functional Keywords: virulence factor, lipoprotein, ligand for complement factor h, protein binding
• Biological source: Neisseria meningitidis
• Total number of polymer chains: 2
• Total formula weight: 59274.54

Authors

Konar, M.,Beernink, P.T. (deposition date: 2015-03-31, release date: 2015-11-04, Last modification date: 2023-09-27)

Primary citation

Konar, M.,Pajon, R.,Beernink, P.T.
A meningococcal vaccine antigen engineered to increase thermal stability and stabilize protective epitopes.
Proc.Natl.Acad.Sci.USA, 112:14823-14828, 2015

PubMed Abstract: Factor H binding protein (FHbp) is part of two vaccines recently licensed for prevention of sepsis and meningitis caused by serogroup B meningococci. FHbp is classified in three phylogenic variant groups that have limited antigenic cross-reactivity, and FHbp variants in one of the groups have low thermal stability. In the present study, we replaced two amino acid residues, R130 and D133, in a stable FHbp variant with their counterparts (L and G) from a less stable variant. The single and double mutants decreased thermal stability of the amino- (N-) terminal domain compared with the wild-type protein as measured by scanning calorimetry. We introduced the converse substitutions, L130R and G133D, in a less stable wild-type FHbp variant, which increased the transition midpoint (Tm) for the N-terminal domain by 8 and 12 °C; together the substitutions increased the Tm by 21 °C. We determined the crystal structure of the double mutant FHbp to 1.6 Å resolution, which showed that R130 and D133 mediated multiple electrostatic interactions. Monoclonal antibodies specific for FHbp epitopes in the N-terminal domain had higher binding affinity for the recombinant double mutant by surface plasmon resonance and to the mutant expressed on meningococci by flow cytometry. The double mutant also had decreased binding of human complement Factor H, which in previous studies increased the protective antibody responses. The stabilized mutant FHbp thus has the potential to stabilize protective epitopes and increase the protective antibody responses to recombinant FHbp vaccines or native outer membrane vesicle vaccines with overexpressed FHbp.

PubMed: 26627237
DOI: 10.1073/pnas.1507829112

Experimental method

X-RAY DIFFRACTION (1.62 Å)