Tissue plasminogen activator（abbreviated PLAT or tPA) is a secreted serine proteasewhich converts the proenzymeplasminogento plasmin， a fibrinolyticenzyme. Plasminogen is synthesized as a single chain which is cleaved by PLAT into the two chain disulfide linked plasmin.
This enzyme plays a role in cell migrationand tissue remodeling. Increased enzymatic activity causes hyperfibrinolysis， which manifests as excessive bleeding； decreased activity leads to hypofibrinolysiswhich can result in thrombosisor embolism.
