%0 Journal Article %A WHITING, G.C. %A EVANS, J.T. %A PATEL, S. %A GILLESPIE, S.H. %T Purification of native α-enolase from Streptococcus pneumoniae that binds plasminogen and is immunogenic %D 2002 %J Journal of Medical Microbiology, %V 51 %N 10 %P 837-843 %@ 1473-5644 %R https://doi.org/10.1099/0022-1317-51-10-837 %I Microbiology Society, %X Many pathogenic bacteria express plasminogen receptors on their surface, which may play a role in the dissemination of organisms by binding plasminogen that, when converted to plasmin, can digest extracellular matrix proteins. A 45-kDa protein was purified from Streptococcus pneumoniae and confirmed as an α-enolase by its ability to catalyse the dehydration of 2-phospho-d-glycerate to phosphoenolpyruvate and by N-terminal sequencing. The activity of α-enolase was found in the cytoplasm and in whole cells. Activity was also demonstrated in cell wall fractions, which confirmed that α-enolase is a cytoplasmic antigen also expressed on the surface of S. pneumoniae. The plasminogen-binding activity of α-enolase was examined by Western blot, which showed that purified α-enolase was able to bind human plasminogen. Immunoblots of the purified 45-kDa α-enolase with 22 sera from patients with pneumococcal disease showed binding in 15 cases, indicating that pneumococcal enolase is immunogenic. %U https://www.microbiologyresearch.org/content/journal/jmm/10.1099/0022-1317-51-10-837