title: Identification of a supramolecular functional architecture of Streptococcus mutans adhesin P1 on the bacterial cell surface.
abstract: P1 (antigen I/II) is a sucrose-independent adhesin of Streptococcus mutans whose functional architecture on the cell surface is not fully understood. S. mutans cells subjected to mechanical extraction were significantly diminished in adherence to immobilized salivary agglutinin but remained immunoreactive and were readily aggregated by fluid-phase salivary agglutinin. Bacterial adherence was restored by incubation of postextracted cells with P1 fragments that contain each of the two known adhesive domains. In contrast to untreated cells, glutaraldehyde-treated bacteria gained reactivity with anti-C-terminal monoclonal antibodies (mAbs), whereas epitopes recognized by mAbs against other portions of the molecule were masked. Surface plasmon resonance experiments demonstrated the ability of apical and C-terminal fragments of P1 to interact. Binding of several different anti-P1 mAbs to unfixed cells triggered release of a C-terminal fragment from the bacterial surface, suggesting a novel mechanism of action of certain adherence-inhibiting antibodies. We also used atomic force microscopy-based single molecule force spectroscopy with tips bearing various mAbs to elucidate the spatial organization and orientation of P1 on living bacteria. The similar rupture lengths detected using mAbs against the head and C-terminal regions, which are widely separated in the tertiary structure, suggest a higher order architecture in which these domains are in close proximity on the cell surface. Taken together, our results suggest a supramolecular organization in which additional P1 polypeptides, including the C-terminal segment originally identified as antigen II, associate with covalently attached P1 to form the functional adhesive layer.
authors: From the Department of Oral Biology, University of Florida, Gainesville, Florida 32610 and.
authors: Kyle P
authors: KP
authors: Heim
authors: Institute of Life Sciences, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium.
authors: Ruby May A
authors: RM
authors: Sullan
authors: From the Department of Oral Biology, University of Florida, Gainesville, Florida 32610 and.
authors: Paula J
authors: PJ
authors: Crowley
authors: Institute of Life Sciences, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium.
authors: Sofiane
authors: S
authors: El-Kirat-Chatel
authors: Institute of Life Sciences, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium.
authors: Audrey
authors: A
authors: Beaussart
authors: From the Department of Oral Biology, University of Florida, Gainesville, Florida 32610 and.
authors: Wenxing
authors: W
authors: Tang
authors: From the Department of Oral Biology, University of Florida, Gainesville, Florida 32610 and.
authors: Richard
authors: R
authors: Besingi
authors: Institute of Life Sciences, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium Yves.Dufrene@uclouvain.be.
authors: Yves F
authors: YF
authors: Dufrene
authors: From the Department of Oral Biology, University of Florida, Gainesville, Florida 32610 and jbrady@dental.ufl.edu.
authors: L Jeannine
authors: LJ
authors: Brady
mesh_terms: D018829:Adhesins, Bacterial / Q000378:metabolism*; D001422:Bacterial Adhesion; D001483:Base Sequence; D015153:Blotting, Western; D017931:DNA Primers; D004591:Electrophoresis, Polyacrylamide Gel; D018625:Microscopy, Atomic Force; D016133:Polymerase Chain Reaction; D013295:Streptococcus mutans / Q000378:metabolism* / Q000502:physiology; D020349:Surface Plasmon Resonance
chemical_list: D018829:Adhesins, Bacterial; D017931:DNA Primers
keywords: Atomic Force Microscopy (AFM); Bacterial Adhesion; Bacterial Surface Architecture; Electron Microscopy (EM); Streptococcus; Surface Plasmon Resonance (SPR)