Streptokinases

Definition

Streptokinases are enzymes produced by certain strains of streptococci that convert plasminogen to plasmin, leading to the breakdown of blood clots. They are considered virulence factors because they help bacteria invade host tissues.

5 Must Know Facts For Your Next Test

1. Streptokinases facilitate bacterial spread by breaking down fibrin clots that would otherwise confine the bacteria.
2. They are commonly produced by Streptococcus pyogenes, a pathogen responsible for various infections such as strep throat and necrotizing fasciitis.
3. In medical settings, synthetic forms of streptokinase are used as clot-dissolving medications in the treatment of acute myocardial infarction (heart attack).
4. The action of streptokinase on plasminogen is not direct; it forms a complex with plasminogen which then converts other plasminogen molecules to plasmin.
5. Resistance to streptokinase can develop due to the body's immune response producing antibodies against it.

Review Questions

• What role does streptokinase play in bacterial virulence?
• Which bacterial species is most notably associated with the production of streptokinase?
• How is streptokinase used in medical treatments?

Related terms

Plasminogen: An inactive precursor protein that is converted into plasmin, an enzyme involved in the breakdown of fibrin clots.

Fibrinolysis: The process through which fibrin clots are broken down, often facilitated by enzymes like plasmin.

Virulence Factor: Any characteristic or component of a pathogen that contributes to its ability to cause disease.