Cloning and characterization of an α-enolase of the oral pathogen Streptococcus mutans that binds human plasminogen

Abstract

Streptococcus mutans is the etiologic agent of dental caries and is a causative agent of infective endocarditis. While the mechanisms by which S. mutans cells colonize heart tissue is not clear, it is thought that bacterial binding to extracellular matrix and blood components is crucial in the development of endocarditis. Previously, we have demonstrated that S. mutans cells have the capacity to bind and activate plasminogen to plasmin. Here we report the first cloning and characterization of an alpha-enolase of S. mutans that binds plasminogen. The functional identity of the purified recombinant alpha-enolase protein was confirmed by its ability to catalyze the conversion of 2-phosphoglycerate to phosphoenolpyruvate. The protein exhibited a Km of 9.5 mM and a Vmax of 31.0 mM/min/mg. The alpha-enolase protein was localized in the cytoplasmic, cell wall and extracellular fractions of S. mutans. Binding studies using an immunoblot analysis revealed that human plasminogen binds to the enolase enzyme of S. mutans. These findings identify S. mutans alpha-enolase as a binding molecule used by this oral pathogen to interact with the blood component, plasminogen. Further studies of this interaction may be critical to understand the pathogenesis of endocarditis caused by S. mutans.

Antibacterial activity, cytotoxicity and mechanical behavior of nano-enhanced denture base resin with different kinds of inorganic antibacterial agents

“…More importantly, virulent factor released from denture plaque is known to be a significant risk factor for opportunistic infections and aspiration pneumonia especially in elderly people and in individuals who are immunocompromised 15) . Streptococcus mutans is regarded as a major etiological agent of dental caries 16) while Candida is a common bacteria which may cause Candida-associated denture stomatitis 17) . Thus, a restorative material that possesses antibacterial properties and inhibits bacterial growth around the restoration would be desirable.…”

Production ofPlasmodium vivaxenolase inEscherichia coliand its protective properties

“…Enolase was identified as a multifunctional protein, involved in the pathogenicity in several Streptococcus by binding the plasminogen of an infected host, 13,14 including the bacterial migration across the mammalian extracellular matrix, 15 and an important antigen using immunoproteomics analysis of extracellular and cell-wall associated proteins of SS2. 16,17 So far, several reports have shown that the enolase of several types of GC bacteria could activate plasminogen and then the surface-bond plasmin could degrade extracellular matrix and laminin, and facilitate penetration of the organism through reconstituted basement membrane, 18 suggesting that anti-Enolase antibodies could be important as an adjunctive vaccine.…”

Inactivation of a gene for a fibronectin-binding protein of the oral bacterium Streptococcus mutans partially impairs its adherence to fibronectin

“…Recombinant S. mutans fibronectin-binding protein (rSmFnB) was purified from 1 liter cultures induced and processed using denaturing conditions as described previously using the Qiagen protocol [26]. To determine the purity of eluted protein, samples collected from the metal affinity column were separated on a 10% SDS-PAGE gel and transferred onto a nitrocellulose membrane and probed with mouse anti-His antibodies.…”