A protease nexin and serpin subtype that is specific for several SERINE PROTEASES including UROKINASE; THROMBIN; TRYPSIN; and PLASMINOGEN ACTIVATORS.

A family of serine proteinase inhibitors which are similar in amino acid sequence and mechanism of inhibition, but differ in their specificity toward proteolytic enzymes. This family includes alpha 1-antitrypsin, angiotensinogen, ovalbumin, antiplasmin, alpha 1-antichymotrypsin, thyroxine-binding protein, complement 1 inactivators, antithrombin III, heparin cofactor II, plasminogen inactivators, gene Y protein, placental plasminogen activator inhibitor, and barley Z protein. Some members of the serpin family may be substrates rather than inhibitors of SERINE ENDOPEPTIDASES, and some serpins occur in plants where their function is not known.

Exogenous or endogenous compounds which inhibit SERINE ENDOPEPTIDASES.

Plasma glycoprotein member of the serpin superfamily which inhibits TRYPSIN; NEUTROPHIL ELASTASE; and other PROTEOLYTIC ENZYMES.

Glycoprotein found in alpha(1)-globulin region in human serum. It inhibits chymotrypsin-like proteinases in vivo and has cytotoxic killer-cell activity in vitro. The protein also has a role as an acute-phase protein and is active in the control of immunologic and inflammatory processes, and as a tumor marker. It is a member of the serpin superfamily.

Endogenous factors and drugs that directly inhibit the action of THROMBIN, usually by blocking its enzymatic activity. They are distinguished from INDIRECT THROMBIN INHIBITORS, such as HEPARIN, which act by enhancing the inhibitory effects of antithrombins.

A member of the serpin family of proteins that is found in plasma and urine. It is dependent on heparin and is able to inhibit activated PROTEIN C; THROMBIN; KALLIKREIN; and other SERINE ENDOPEPTIDASES.

Serum proteins that inhibit, antagonize, or inactivate COMPLEMENT C1 or its subunits.

Extracellular protease inhibitors that are secreted from FIBROBLASTS. They form a covalent complex with SERINE PROTEASES and can mediate their cellular internalization and degradation.

The type species of LEPORIPOXVIRUS causing infectious myxomatosis, a severe generalized disease, in rabbits. Tumors are not always present.

Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.

Member of the serpin family of proteins. It inhibits both the tissue-type and urokinase-type plasminogen activators.

The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.

A species of ORTHOPOXVIRUS that is the etiologic agent of COWPOX. It is closely related to but antigenically different from VACCINIA VIRUS.

An enzyme that catalyzes the hydrolysis of proteins, including elastin. It cleaves preferentially bonds at the carboxyl side of Ala and Val, with greater specificity for Ala. EC 3.4.21.37.

A member of the serpin family of proteins. It inhibits both the tissue-type and urokinase-type plasminogen activators.