Factor XIIIa: Activated form of FACTOR XIII, a transglutaminase, which stabilizes the formation of the fibrin polymer (clot) culminating the blood coagulation cascade.Factor XIII: A fibrin-stabilizing plasma enzyme (TRANSGLUTAMINASES) that is activated by THROMBIN and CALCIUM to form FACTOR XIIIA. It is important for stabilizing the formation of the fibrin polymer (clot) which culminates the coagulation cascade.Transglutaminases: Transglutaminases catalyze cross-linking of proteins at a GLUTAMINE in one chain with LYSINE in another chain. They include keratinocyte transglutaminase (TGM1 or TGK), tissue transglutaminase (TGM2 or TGC), plasma transglutaminase involved with coagulation (FACTOR XIII and FACTOR XIIIa), hair follicle transglutaminase, and prostate transglutaminase. Although structures differ, they share an active site (YGQCW) and strict CALCIUM dependence.Fibrin: A protein derived from FIBRINOGEN in the presence of THROMBIN, which forms part of the blood clot.Cadaverine: A foul-smelling diamine formed by bacterial decarboxylation of lysine.Factor XIII Deficiency: A deficiency of blood coagulation FACTOR XIII or fibrin stabilizing factor (FSF) that prevents blood clot formation and results in a clinical hemorrhagic diathesis.Cross-Linking Reagents: Reagents with two reactive groups, usually at opposite ends of the molecule, that are capable of reacting with and thereby forming bridges between side chains of amino acids in proteins; the locations of naturally reactive areas within proteins can thereby be identified; may also be used for other macromolecules, like glycoproteins, nucleic acids, or other.Afibrinogenemia: A deficiency or absence of FIBRINOGEN in the blood.Fibrinogen: Plasma glycoprotein clotted by thrombin, composed of a dimer of three non-identical pairs of polypeptide chains (alpha, beta, gamma) held together by disulfide bonds. Fibrinogen clotting is a sol-gel change involving complex molecular arrangements: whereas fibrinogen is cleaved by thrombin to form polypeptides A and B, the proteolytic action of other enzymes yields different fibrinogen degradation products.Glutamine: A non-essential amino acid present abundantly throughout the body and is involved in many metabolic processes. It is synthesized from GLUTAMIC ACID and AMMONIA. It is the principal carrier of NITROGEN in the body and is an important energy source for many cells.Fibrinogens, Abnormal: Fibrinogens which have a functional defect as the result of one or more amino acid substitutions in the amino acid sequence of normal fibrinogen. Abnormalities of the fibrinogen molecule may impair any of the major steps involved in the conversion of fibrinogen into stabilized fibrin, such as cleavage of the fibrinopeptides by thrombin, polymerization and cross-linking of fibrin. The resulting dysfibrinogenemias can be clinically silent or can be associated with bleeding, thrombosis or defective wound healing.Fibrinopeptide B: Two small peptide chains removed from the N-terminal segment of the beta chains of fibrinogen by the action of thrombin. Each peptide chain contains 20 amino acid residues. The removal of fibrinopeptides B is not required for coagulation.alpha-2-Antiplasmin: A member of the serpin superfamily found in plasma that inhibits the lysis of fibrin clots which are induced by plasminogen activator. It is a glycoprotein, molecular weight approximately 70,000 that migrates in the alpha 2 region in immunoelectrophoresis. It is the principal plasmin inactivator in blood, rapidly forming a very stable complex with plasmin.Thrombin: An enzyme formed from PROTHROMBIN that converts FIBRINOGEN to FIBRIN.Putrescine: A toxic diamine formed by putrefaction from the decarboxylation of arginine and ornithine.Amino Acid Sequence: 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.Non-Fibrillar Collagens: A family of structurally-related short-chain collagens that do not form large fibril bundles.Guinea Pigs: A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.Fibrinolysis: The natural enzymatic dissolution of FIBRIN.Blood Coagulation: The process of the interaction of BLOOD COAGULATION FACTORS that results in an insoluble FIBRIN clot.Dermis: A layer of vascularized connective tissue underneath the EPIDERMIS. The surface of the dermis contains innervated papillae. Embedded in or beneath the dermis are SWEAT GLANDS; HAIR FOLLICLES; and SEBACEOUS GLANDS.gamma-Glutamyltransferase: An enzyme, sometimes called GGT, with a key role in the synthesis and degradation of GLUTATHIONE; (GSH, a tripeptide that protects cells from many toxins). It catalyzes the transfer of the gamma-glutamyl moiety to an acceptor amino acid.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Caseins: A mixture of related phosphoproteins occurring in milk and cheese. The group is characterized as one of the most nutritive milk proteins, containing all of the common amino acids and rich in the essential ones.Kinetics: The rate dynamics in chemical or physical systems.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Oligopeptides: Peptides composed of between two and twelve amino acids.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.