Related Research Articles
Hemocyanins (also spelled haemocyanins and abbreviated Hc) are proteins that transport oxygen throughout the bodies of some invertebrate animals. These metalloproteins contain two copper atoms that reversibly bind a single oxygen molecule (O2). They are second only to hemoglobin in frequency of use as an oxygen transport molecule. Unlike the hemoglobin in red blood cells found in vertebrates, hemocyanins are not confined in blood cells but are instead suspended directly in the hemolymph. Oxygenation causes a color change between the colorless Cu(I) deoxygenated form and the blue Cu(II) oxygenated form.
Coagulation, also known as clotting, is the process by which blood changes from a liquid to a gel, forming a blood clot. It potentially results in hemostasis, the cessation of blood loss from a damaged vessel, followed by repair. The mechanism of coagulation involves activation, adhesion and aggregation of platelets, as well as deposition and maturation of fibrin.
The Atlantic horseshoe crab, also known as the American horseshoe crab, is a species of horseshoe crab, a kind of marine and brackish chelicerate arthropod. It is found in the Gulf of Mexico and along the Atlantic coast of North America. The main area of annual migration is Delaware Bay along the South Jersey Delaware Bayshore.
Coagulation factor XII, also known as Hageman factor, is a plasma protein. It is the zymogen form of factor XIIa, an enzyme of the serine protease class. In humans, factor XII is encoded by the F12 gene.
Plasmin is an important enzyme present in blood that degrades many blood plasma proteins, including fibrin clots. The degradation of fibrin is termed fibrinolysis. In humans, the plasmin protein is encoded by the PLG gene.
Horseshoe crabs are marine and brackish water arthropods of the family Limulidae and the only living members of the order Xiphosura. Despite their name, they are not true crabs or crustaceans: they are chelicerates, most closely related to arachnids such as spiders, ticks, and scorpions.
Protein C, also known as autoprothrombin IIA and blood coagulation factor XIV, is a zymogen, that is, an inactive enzyme. The activated form plays an important role in regulating anticoagulation, inflammation, and cell death and maintaining the permeability of blood vessel walls in humans and other animals. Activated protein C (APC) performs these operations primarily by proteolytically inactivating proteins Factor Va and Factor VIIIa. APC is classified as a serine protease since it contains a residue of serine in its active site. In humans, protein C is encoded by the PROC gene, which is found on chromosome 2.
Plasminogen activators are serine proteases that catalyze the activation of plasmin via proteolytic cleavage of its zymogen form plasminogen. Plasmin is an important factor in fibrinolysis, the breakdown of fibrin polymers formed during blood clotting. There are two main plasminogen activators: urokinase (uPA) and tissue plasminogen activator (tPA). Tissue plasminogen activators are used to treat medical conditions related to blood clotting including embolic or thrombotic stroke, myocardial infarction, and pulmonary embolism.
Limulus amebocyte lysate (LAL) is an aqueous extract of motile blood cells (amebocytes) from the Atlantic horseshoe crab Limulus polyphemus. LAL reacts with bacterial endotoxins such as lipopolysaccharides (LPS), which are components of the bacterial capsule, the outermost membrane of cell envelope of gram-negative bacteria. This reaction is the basis of the LAL test, which is widely used for the detection and quantification of bacterial endotoxins.
Kininogens are precursor proteins for kinins, biologically active polypeptides involved in blood coagulation, vasodilation, smooth muscle contraction, inflammatory regulation, and the regulation of the cardiovascular and renal systems.
An amebocyte or amoebocyte is a motile cell in the bodies of invertebrates including cnidaria, echinoderms, molluscs, tunicates, sponges, and some chelicerates.
Tachypleus gigas, commonly known as the Indo-Pacific horseshoe crab, Indonesian horseshoe crab, Indian horseshoe crab, or southern horseshoe crab, is one of the four extant (living) species of horseshoe crab. It is found in coastal water in South and Southeast Asia at depths to 40 m (130 ft).
Coagulin is a gel-forming protein of hemolymph that hinders the spread of bacterial and fungal invaders by immobilizing them. It is produced in the coagulogen form before being cleaved into the active form through a serine proteinase cascade. It has been most extensively studied in horseshoe crabs. It has also been produced by other organisms, such as Bacillus coagulans I4 in a plasmid location. In human medicine, coagulation of coagulin is the basis of detection of bacterial endotoxin through the Limulus amebocyte lysate test for parenteral medications.
Limulus clotting factor overbar C is an enzyme. This enzyme catalyses the following chemical reaction
Limulus clotting factor B is an enzyme. This enzyme catalyses the following chemical reaction
Snake venom factor V activator is an enzyme. This enzyme catalyses the following chemical reaction
Russellysin is an enzyme. This enzyme catalyses the following chemical reaction
Tachyplesin is an antimicrobial peptide isolated from the horseshoe crab with a molecular weight of 2.36 kDa and the amino acid sequence KWCFRVCYRGICYRRCR.
H. Jane Brockmann is an emeritus professor at the University of Florida known for her research on animal behavior, especially in the mating and nesting behavior of horseshoe crabs. In 2008, she was elected a fellow of the American Association for the Advancement of Science.
Jack Levin is an American physician-scientist and hematologist who, with Fred Bang, developed the Limulus amebocyte lysate (LAL) test for bacterial endotoxins.
References
- ↑ Muta T, Hashimoto R, Miyata T, Nishimura H, Toh Y, Iwanaga S (December 1990). "Proclotting enzyme from horseshoe crab hemocytes. cDNA cloning, disulfide locations, and subcellular localization". The Journal of Biological Chemistry. 265 (36): 22426–33. doi: 10.1016/S0021-9258(18)45722-5 . PMID 2266134.
- ↑ Tokunaga F, Nakajima H, Iwanaga S (January 1991). "Further studies on lipopolysaccharide-sensitive serine protease zymogen (factor C): its isolation from Limulus polyphemus hemocytes and identification as an intracellular zymogen activated by alpha-chymotrypsin, not by trypsin". Journal of Biochemistry. 109 (1): 150–7. doi:10.1093/oxfordjournals.jbchem.a123337. PMID 2016264.
- ↑ Iwanaga, S (May 2007). "Biochemical principle of Limulus test for detecting bacterial endotoxins". Proceedings of the Japan Academy. Series B, Physical and Biological Sciences. 83 (4): 110–9. Bibcode:2007PJAB...83..110I. doi:10.2183/pjab.83.110. PMC 3756735 . PMID 24019589.
