0000000000401100
AUTHOR
Abdelhakim Ben Nasr
Absorption of kininogen from human plasma by Streptococcus pyogenes is followed by the release of bradykinin.
H-kininogen (high-molecular-mass kininogen, HK) is the precursor of the vasoactive peptide hormone bradykinin (BK). Previous work has demonstrated that HK binds to Streptococcus pyogenesthrough M-proteins, fibrous surface proteins and important virulence factors of these bacteria. Here we find that M-protein-expressing bacteria absorb HK from human plasma. The HK bound to the bacteria was found to be cleaved, and analysis of the degradation pattern suggested that the cleavage of HK at the bacterial surface is associated with the release of BK. Moreover, addition of activated plasma prekallikrein to bacteria preincubated with human plasma, resulted in BK release. This mechanism, by which a p…
Assembly of human contact phase proteins and release of bradykinin at the surface of curli-expressing Escherichia coli.
Previous work has demonstrated that most strains of the human pathogen Streptococcus pyogenes bind kininogens through M protein, a fibrous surface protein and virulence determinant. Here we find that strains of several other pathogenic bacterial species, both Gram-positive and Gram-negative, isolated from patients with sepsis, also bind kininogens, especially kininogen (HK). The most pronounced interaction was seen between HK and Escherichia coli. Among clinical isolates of E. coli, the majority of the enterohaemorrhagic, enterotoxigenic, and sepsis strains, but none of the enteroinvasive and enteropathogenic strains, bound HK. Binding of HK to E. coli correlated with the expression of curl…