Identification of enolase as a laminin-binding protein on the surface of Staphylococcus aureus.
We have previously demonstrated that Staphylococcus aureus, a highly invasive bacteria, presents a 52-kDa surface protein that mediates its binding to laminin. In order to better characterize this receptor, we excised this putative laminin receptor from two-dimensional (2-D) PAGE and used it as antigen for raising a mouse hyperimmune serum which was for screening an S. aureus expression library. A single clone of 0.3 kb was obtained, and its sequence revealed 100% homology with S. aureus alpha-enolase. Moreover, amino acid sequencing of the 52-kDa protein eluted from the 2-D gel indicated its molecular homology with alpha-enolase, an enzyme that presents a high evolutionary conservation among species. In parallel, monoclonal antibodies raised against the S. aureus 52-kDa band also recognized yeast alpha-enolase in western blot analysis. These monoclonal antibodies were also able to promote capture of iodine-labeled bacteria when adsorbed to a solid phase, and this capture was inhibited by the addition of excess rabbit muscle alpha-enolase. Finally, the cell surface localization of S. aureus alpha-enolase was further confirmed by flow cytometry. Hence, alpha-enolase might play a critical role in the pathogenesis of S. aureus by allowing its adherence to laminin-containing extracellular matrix.
Carneiro
Celia R W
CR
Discipline of Immunology, Microbiology, Immunology and Parasitology Department, Federal University of São Paulo, São Paulo, Brazil.
Postol
Edilberto
E
Nomizo
Regina
R
Reis
Luiz F L
LF
Brentani
Ricardo R
RR
D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004269:DNA, Bacterial / Q000737:chemistry / Q000302:isolation & purification; D015723:Gene Library; D005798:Genes, Bacterial; D007797:Laminin / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D010751:Phosphopyruvate Hydratase / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011485:Protein Binding; D017474:Receptors, Laminin / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D017385:Sequence Homology; D013211:Staphylococcus aureus / Q000201:enzymology* / Q000472:pathogenicity
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D007797:Laminin; D008565:Membrane Proteins; D017474:Receptors, Laminin; D010751:Phosphopyruvate Hydratase