Hemovanadin is a pale green vanabin protein found in the blood cells, called vanadocytes, of ascidians (sea squirts) and other organisms (particularly sea organisms). [1] It is one of the few known vanadium-containing proteins. [2] [3] The German chemist Martin Henze first detected vanadium in ascidians (sea squirts) in 1911. [4] [5] Unlike hemocyanin and hemoglobin, hemovanadin is not an oxygen carrier. [6] [7]
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the circulatory system is also known as peripheral blood, and the blood cells it carries, peripheral blood cells.
Hemoglobin, abbreviated Hb or Hgb, is the iron-containing oxygen-transport protein present in red blood cells (erythrocytes) of almost all vertebrates as well as the tissues of some invertebrate animals. Hemoglobin in blood carries oxygen from the respiratory organs to the other tissues of the body, where it releases the oxygen to enable aerobic respiration which powers the animal's metabolism. A healthy human has 12 to 20 grams of hemoglobin in every 100 mL of blood. Hemoglobin is a metalloprotein and chromoprotein.
Vanadium is a chemical element with the symbol V and atomic number 23. It is a hard, silvery-grey, malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an oxide layer (passivation) somewhat stabilizes the free metal against further oxidation.
Symbiogenesis is the leading evolutionary theory of the origin of eukaryotic cells from prokaryotic organisms. The theory holds that mitochondria, plastids such as chloroplasts, and possibly other organelles of eukaryotic cells are descended from formerly free-living prokaryotes taken one inside the other in endosymbiosis. Mitochondria appear to be phylogenetically related to Rickettsiales bacteria, while chloroplasts are thought to be related to cyanobacteria.
Mycoplasma is a genus of bacteria that, like the other members of the class Mollicutes, lack a cell wall around their cell membranes. Peptidoglycan (murein) is absent. This characteristic makes them naturally resistant to antibiotics that target cell wall synthesis. They can be parasitic or saprotrophic. Several species are pathogenic in humans, including M. pneumoniae, which is an important cause of "walking" pneumonia and other respiratory disorders, and M. genitalium, which is believed to be involved in pelvic inflammatory diseases. Mycoplasma species are among the smallest organisms yet discovered, can survive without oxygen, and come in various shapes. For example, M. genitalium is flask-shaped, while M. pneumoniae is more elongated, many Mycoplasma species are coccoid. Hundreds of Mycoplasma species infect animals.
A tunicate is a marine invertebrate animal, a member of the subphylum Tunicata. It is part of the Chordata, a phylum which includes all animals with dorsal nerve cords and notochords. The subphylum was at one time called Urochordata, and the term urochordates is still sometimes used for these animals. They are the only chordates that have lost their myomeric segmentation, with the possible exception of the 'seriation of the gill slits'. However, doliolids still display segmentation of the muscle bands.
Group 5 is a group of elements in the periodic table. Group 5 contains vanadium (V), niobium (Nb), tantalum (Ta) and dubnium (Db). This group lies in the d-block of the periodic table. This group is sometimes called the vanadium group or vanadium family after its lightest member; however, the group itself has not acquired a trivial name because it belongs to the broader grouping of the transition metals.
Ascidiacea, commonly known as the ascidians or sea squirts, is a paraphyletic class in the subphylum Tunicata of sac-like marine invertebrate filter feeders. Ascidians are characterized by a tough outer "tunic" made of a polysaccharide.
Vanabins are a group of vanadium-binding metalloproteins. Vanabins are found almost exclusively in the blood cells, or vanadocytes, of some tunicates, including the Ascidiacea. The vanabins extracted from tunicate vanadocytes are often called hemovanadins. These organisms are able to concentrate vanadium from the surrounding seawater, and vanabin proteins have been involved in collecting and accumulating this metal ion. At present there is no conclusive understanding of why these organisms collect vanadium.
Sir Richard Timothy Hunt, is a British biochemist and molecular physiologist. He was awarded the 2001 Nobel Prize in Physiology or Medicine with Paul Nurse and Leland H. Hartwell for their discoveries of protein molecules that control the division of cells. While studying fertilized sea urchin eggs in the early 1980s, Hunt discovered cyclin, a protein that cyclically aggregates and is depleted during cell division cycles.
Ciona intestinalis is an ascidian, a tunicate with very soft tunic. Its Latin name literally means "pillar of intestines", referring to the fact that its body is a soft, translucent column-like structure, resembling a mass of intestines sprouting from a rock. It is a globally distributed cosmopolitan species. Since Linnaeus described the species, Ciona intestinalis has been used as a model invertebrate chordate in developmental biology and genomics. Studies conducted between 2005 and 2010 have shown that there are at least two, possibly four, sister species. More recently it has been shown that one of these species has already been described as Ciona robusta. By anthropogenic means, the species has invaded various parts of the world and is known as an invasive species.
Protozoa are a polyphyletic group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic debris. Historically, protozoans were regarded as "one-celled animals", because they often possess animal-like behaviours, such as motility and predation, and lack a cell wall, as found in plants and many algae.
Amoeba is a genus of single-celled amoeboids in the family Amoebidae. The type species of the genus is Amoeba proteus, a common freshwater organism, widely studied in classrooms and laboratories.
Clavelina picta, common name the painted tunicate, is a species of tunicate, in the genus Clavelina. These animals, like all ascidians, are sessile filter feeders.
Prochloron is a genus of unicellular oxygenic photosynthetic prokaryotes commonly found as an extracellular symbiont on coral reefs, particularly in didemnid ascidians. Part of the phylum cyanobacteria, it was theorized that Prochloron is a predecessor of the photosynthetic components, chloroplasts, found in photosynthetic eukaryotic cells. However this theory is largely refuted by phylogenetic studies which indicate Prochloron is not on the same line of descent that lead to chloroplast-containing algae and land plants.
Ecteinascidia turbinata, commonly known as the mangrove tunicate, is a species of sea squirt species in the family Perophoridae. It was described to science in 1880 by William Abbott Herdman. The cancer drug trabectedin is isolated from E. turbinata.
Phallusia mammillata is a solitary marine tunicate of the ascidian class found in the eastern Atlantic Ocean and the Mediterranean Sea.
Friedrich Wolfgang Martin Henze was a German chemist.
Clavelina minuta is a species of sea squirt found in Japan, that has been demonstrated to produce an intrinsic (non-secreted) green bioluminescence of 535 nm. Notably, this bioluminescence is not thought to be due to bacterial symbionts. Clavelina minuta is currently the only sea squirt (Ascidiacea) known to produce light, however old reports also report luminescence in Botryllus and Ciona. Amongst other tunicates, the unrelated Pyrosoma and Appendicularia, which produce an intrinsic blue light, are bioluminescent, and genera Doliolum (Doliolidae) and Cyclosalpa (Salpidae) may also be bioluminescent.
A vanadocyte is a specialized type of blood cell found in ascidians (tunicates). These cells are notable for their high levels of vanadium (concentrations 107 higher than that of seawater), which is typically a metabolic poison in other contexts.
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