Staphylokinase is a amino acid

Amino acid

Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...

 enzyme

Enzyme

Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

 from Staphylococcus aureus

Staphylococcus aureus

Staphylococcus aureus is a facultative anaerobic Gram-positive coccal bacterium. It is frequently found as part of the normal skin flora on the skin and nasal passages. It is estimated that 20% of the human population are long-term carriers of S. aureus. S. aureus is the most common species of...

. It is positively regulated by the "agr" gene regulator. It activates plasminogen to form plasmin, which digest fibrin clots. This disrupts the fibrin meshwork which can often form to keep an infection localized.

Staphylokinase also cleaves IgG and complement component C3b

C3b

C3b is the larger of two elements formed by the cleavage of complement component 3. C3b covalently bonds to microbial cell surfaces within an organism's body. This leads to the production of surface-bound C3 convertase and thus more C3b components. Bound C3b also aids in opsonization of the microbe...

, inhibiting phagocytosis.

It is classified under .