Open AccessStructural relationship between the S1 and S4 subunits of pertussis toxin
Author(s) -
Sato Hiroko,
Sato Yuji
Publication year - 1994
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1994.tb06615.x
Subject(s) - pertussis toxin , toxin , bordetella pertussis , microbiology and biotechnology , chemistry , biology , bacteria , genetics , biochemistry , receptor , g protein
Pertussis toxin, the most important protective antigen of Bordetella pertussis , is a 106‐kDa hexameric protein composed of an A‐promoter (subunit S1) and a pentameric B‐oligomer (S2 + S3 + 2S4 + S5). The most potent mouse‐protective monoclonal antibodies against both respiratory and intracerebral infections were specified for either S1 or S4 and competed with each other in binding to epitopes of native pertussis toxin captuted by haptoglobin or in solution, although they did not compete on unfolded pertussin toxin. These data suggest that the protective epitope(s) of S1 and S4 are very closely correlated; they are probably close] together sterically. Non‐protective anti‐S1 and anti‐S4 monoclonal antibodies recognized inner antigenic determinants which are not exposed on the surface o native pertussis toxin and interfered with association of the A‐protomer and the B‐oligomer. These data suggest that the A‐protomer and the S4 subunit of the B‐oligomer may be closely associated in the native hexameric pertussis toxin molecule.