Two-dimensional structure of the Opc invasin from Neisseria meningitidis.
A two-dimensional structural model was devised for the Opc outer membrane protein invasin which contains 10 transmembrane strands and five surface-exposed loops. One continuous epitope recognized by three monoclonal antibodies was localized to the tip of loop 2 by synthetic peptides and site-directed mutagenesis while a second, discontinuous epitope recognized by a fourth antibody was localized to loops 4 and 5 by insertion mutagenesis. These monoclonal antibodies are bactericidal and inhibit adhesion and invasion. Most of the T-cell epitopes defined by Wiertz et al. (1996) were localized to the transmembrane strands. Oligonucleotides encoding a foreign epitope (nabla) from Semliki Forest virus were inserted into BglII restriction sites created by site-directed mutagenesis. The nabla epitopes inserted in all five predicted loops were recognized on the cell surface of live Escherichia coli bacteria by a monoclonal antibody and are exposed while nabla epitopes in the N-terminus or three predicted turns were not. The results thus confirm important predictions of the model and define five permissive sites within surface-exposed loops which can be used to insert foreign epitopes.
Merker
P
P
Max-Planck Institut für molekulare Genetik, Berlin, Germany.
Tommassen
J
J
Kusecek
B
B
Virji
M
M
Sesardic
D
D
Achtman
M
M
D018829:Adhesins, Bacterial; D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry* / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry*; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D008969:Molecular Sequence Data; D009345:Neisseria meningitidis / Q000737:chemistry* / Q000235:genetics; D017433:Protein Structure, Secondary
D018829:Adhesins, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; C053476:invasin, Yersinia; C074517:opc protein, bacteria