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Allelic variants of streptokinase from Streptococcus pyogenes display functional differences in plasminogen activation
Author(s) -
McArthur Jason D.,
McKay Fiona C.,
Ramachandran Vidiya,
Shyam Priya,
Cork Amanda J.,
SandersonSmith Martina L.,
Cole Jason N.,
Ringdahl Ulrika,
Sjöbring Ulf,
Ranson Marie,
Walker Mark J.
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.08-109348
Subject(s) - streptokinase , streptococcus pyogenes , plasmin , microbiology and biotechnology , biology , pathogenesis , allele , virulence , bacteria , gene , genetics , enzyme , biochemistry , immunology , medicine , staphylococcus aureus , psychiatry , myocardial infarction
A common mammalian defense mechanism employed to prevent systemic dissemination of invasive bacteria involves occlusion of local microvasculature and encapsulation of bacteria within fibrin networks. Acquisition of plasmin activity at the bacterial cell surface circumvents this defense mechanism, allowing invasive disease initiation. To facilitate this process, S. pyogenes secretes streptokinase, a plasminogen‐activating protein. Streptokinase polymorphism exhibited by S. pyogenes isolates is well characterized. However, the functional differences displayed by these variants and the biological significance of this variation has not been elucidated. Phylogenetic analysis of ska sequences from 28 S. pyogenes isolates revealed 2 main sequence clusters (clusters 1 and 2). All strains secreted streptokinase, as determined by Western blotting, and were capable of acquiring cell surface plasmin activity after incubation in human plasma. Whereas culture supernatants from strains containing cluster 1 ska alleles also displayed soluble plasminogen activation activity, supernatants from strains containing cluster 2 ska alleles did not. Furthermore, plasminogen activation activity in culture supernatants from strains containing cluster 2 ska alleles could only be detected when plasminogen was prebound with fibrinogen. This study indicates that variant streptokinase proteins secreted by S. pyogenes isolates display differing plasminogen activation characteristics and may therefore play distinct roles in disease pathogenesis.—McArthur, J. D., McKay, F. C., Ramachandran, V., Shyam, P., Cork, A. J., Sanderson‐Smith, M. L., Cole, J. N., Ringdahl, U., Sjöbring, U., Ranson, M., Walker, M. J. Allelic variants of streptokinase from Streptococcus pyogenes display functional differences in plasminogen activation. FASEB J. 22, 3146–3153 (2008)