Growth phase-dependent production of a cell wall-associated elastinolytic cysteine proteinase by Staphylococcus epidermidis.
Staphylococcus epidermidis, a Gram-positive, coagulase-negative bacterium is a predominant inhabitant of human skin and mucous membranes. Recently, however, it has become one of the most important agents of hospital-acquired bacteriemia, as it has been found to be responsible for surgical wound infections developed in individuals with indwelling catheters or prosthetic devices, as well as in immunosupressed or neutropenic patients. Despite their medical significance, little is known about proteolytic enzymes of S. epidermidis and their possible contribution to the bacterium's pathogenicity; however, it is likely that they function as virulence factors in a manner similar to that proposed for the proteases of Staphylococcus aureus. Here we describe the purification of a cell wall-associated cysteine protease from S. epidermidis, its biochemical properties and specificity. A homology search using N-terminal sequence data revealed similarity to staphopain A (ScpA) and staphopain B (SspB), cysteine proteases from S. aureus. Moreover, the gene encoding S. epidermidis cysteine protease (Ecp) and a downstream gene coding for a putative inhibitor of the protease form an operon structure which resembles that of staphopain A in S. aureus. The active cysteine protease was detected on the bacterial cell surface as well as in the culture media and is apparently produced in a growth phase-dependent manner, with initial expression occurring in the mid-logarithmic phase. This enzyme, with elastinolytic properties, as well as the ability to cleave alpha1PI, fibrinogen and fibronectin, may possibly contribute to the invasiveness and pathogenic potential of S. epidermidis.
Oleksy
Aneta
A
Department of Microbiology, Faculty of Biotechnology, Jagiellonian University, 30-387 Krakow, Poland.
Golonka
Ewa
E
Bańbuła
Agnieszka
A
Szmyd
Grzegorz
G
Moon
Jonathan
J
Kubica
Małgorzata
M
Greenbaum
Doron
D
Bogyo
Matthew
M
Foster
Timothy J
TJ
Travis
James
J
Potempa
Jan
J
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000187:drug effects / Q000302:isolation & purification / Q000502:physiology; D002473:Cell Wall / Q000201:enzymology*; D003546:Cysteine Endopeptidases / Q000187:drug effects / Q000302:isolation & purification / Q000502:physiology*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004549:Elastin / Q000378:metabolism*; D004795:Enzyme Stability / Q000187:drug effects / Q000502:physiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D019163:Reducing Agents / Q000494:pharmacology; D017386:Sequence Homology, Amino Acid; D013212:Staphylococcus epidermidis / Q000201:enzymology* / Q000254:growth & development*; D013379:Substrate Specificity
D001426:Bacterial Proteins; D015853:Cysteine Proteinase Inhibitors; D019163:Reducing Agents; D004549:Elastin; D003546:Cysteine Endopeptidases