SufA - a bacterial enzyme that cleaves fibrinogen and blocks fibrin network formation.
Finegoldia magna is a member of the normal human bacterial flora on the skin and other non-sterile body surfaces, but this anaerobic coccus is also an important opportunistic pathogen. SufA was the first F. magna proteinase to be isolated and characterized. Many bacterial pathogens interfere with different steps of blood coagulation, and here we describe how purified SufA efficiently and specifically cleaves fibrinogen in human plasma. SufA is both secreted by F. magna and associated with the bacterial surface. Successful gene targeting has previously not been performed in anaerobic cocci, but in order to study the role of the SufA that is present at the bacterial surface, we constructed an F. magna mutant that expresses a truncated SufA lacking proteolytic activity. In contrast to wild-type bacteria that delayed the coagulation of human plasma, mutant bacteria had no such effect. Wild-type and mutant bacteria adhered to keratinocytes equally well, but in a plasma environment only wild-type bacteria blocked the formation of fibrin networks surrounding adherent bacteria. The effective cleavage of fibrinogen by SufA suggests that the interference with fibrin network formation represents an adaptive mechanism of F. magna with potential implications also for pathogenicity.
Karlsson
Christofer
C
Division of Infection Medicine, Department of Clinical Sciences, Lund University, BMC B14, 221 84 Lund, Sweden.
Mörgelin
Matthias
M
Division of Infection Medicine, Department of Clinical Sciences, Lund University, BMC B14, 221 84 Lund, Sweden.
Collin
Mattias
M
Division of Infection Medicine, Department of Clinical Sciences, Lund University, BMC B14, 221 84 Lund, Sweden.
Lood
Rolf
R
Division of Infection Medicine, Department of Clinical Sciences, Lund University, BMC B14, 221 84 Lund, Sweden.
Andersson
Marie-Louise
ML
Division of Dermatology and Venereology, Department of Clinical Sciences, Lund University, BMC B14, 221 84 Lund, Sweden.
Schmidtchen
Artur
A
Division of Dermatology and Venereology, Department of Clinical Sciences, Lund University, BMC B14, 221 84 Lund, Sweden.
Björck
Lars
L
Division of Infection Medicine, Department of Clinical Sciences, Lund University, BMC B14, 221 84 Lund, Sweden.
Frick
Inga-Maria
IM
Division of Infection Medicine, Department of Clinical Sciences, Lund University, BMC B14, 221 84 Lund, Sweden.
D000693:Anaerobiosis; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D005337:Fibrin / Q000378:metabolism*; D005340:Fibrinogen / Q000378:metabolism*; D018390:Gene Targeting; D006095:Gram-Positive Cocci / Q000201:enzymology* / Q000472:pathogenicity* / Q000502:physiology; D006801:Humans; D015603:Keratinocytes / Q000382:microbiology; D020860:Subtilisin / Q000235:genetics / Q000378:metabolism*; D014169:Transformation, Bacterial
D001426:Bacterial Proteins; D005337:Fibrin; D005340:Fibrinogen; D020860:Subtilisin