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OST Family
Members of the organic solute transporter (OST) familyTC# 2.A.82 (''Slc51'' genes) have been characterized from a small bottom feeding species of fish called the little skate, ''Raja erinacea''. Members have also been characterized from humans and mice. The OST family is a member of the larger group of secondary carriers, the APC Superfamily, APC superfamily. Substrates Substrates for OST transporters include a variety of organic compounds, most being anionic. Transport of estrone sulfate by the two subunit Ost transporter of ''Raja erinacea''TC# 2.A.82.1.1 is Na+-independent, ATP-independent, saturable and inhibited by other steroids and anionic drugs. Bile acids such as taurocholate as well as digoxin and prostaglandin E2 are substrates of this system, while estradiol 17β-D-glucuronide and p-aminohippurate are apparently not. Mammalian homologues (e.g., 2.A.82.1.2) similarly exhibit broad substrate specificity, transporting the same compounds, possibly by an anion:anion exchange ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raja Erinacea
The little skate (''Leucoraja erinacea'') is a species of skate in the family Rajidae, found from Nova Scotia to North Carolina on sand or gravel habitats. They are one of the dominant members of the demersal fish community in the northwestern Atlantic. This species is of minimal commercial importance and is mostly used as bait for lobster traps, though its wings are also marketed for food. It is also important as a model organism for biological and medical research. Distribution and habitat This skate is native to the western Atlantic Ocean, from Nova Scotia, Canada, to Cape Hatteras, North Carolina, USA. They are most abundant in the northern Mid-Atlantic Bight and the Georges Bank. Little skates prefer sandy or gravelly habitats from the shore to a depth of , though they have been caught as deep as . They can tolerate temperatures of and salinities of 27–33.8 ppt (though the optimum is 29–33 ppt). They do not undertake long migrations, but at the inshore parts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osmoregulation
Osmoregulation is the active regulation of the osmotic pressure of an organism's body fluids, detected by osmoreceptors, to maintain the homeostasis of the organism's water content; that is, it maintains the fluid balance and the concentration of electrolytes (salts in solution which in this case is represented by body fluid) to keep the body fluids from becoming too diluted or concentrated. Osmotic pressure is a measure of the tendency of water to move into one solution from another by osmosis. The higher the osmotic pressure of a solution, the more water tends to move into it. Pressure must be exerted on the hypertonic side of a selectively permeable membrane to prevent diffusion of water by osmosis from the side containing pure water. Although there may be hourly and daily variations in osmotic balance, an animal is generally in an osmotic steady state over the long term. Organisms in aquatic and terrestrial environments must maintain the right concentration of solutes and amo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmembrane Transporters
A transmembrane protein (TP) is a type of integral membrane protein that spans the entirety of the cell membrane. Many transmembrane proteins function as gateways to permit the transport of specific substances across the membrane. They frequently undergo significant conformational changes to move a substance through the membrane. They are usually highly hydrophobic and aggregate and precipitate in water. They require detergents or nonpolar solvents for extraction, although some of them (beta-barrels) can be also extracted using denaturing agents. The peptide sequence that spans the membrane, or the transmembrane segment, is largely hydrophobic and can be visualized using the hydropathy plot. Depending on the number of transmembrane segments, transmembrane proteins can be classified as single-span (or bitopic) or multi-span (polytopic). Some other integral membrane proteins are called monotopic, meaning that they are also permanently attached to the membrane, but do not pass t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmembrane Proteins
A transmembrane protein (TP) is a type of integral membrane protein that spans the entirety of the cell membrane. Many transmembrane proteins function as gateways to permit the transport of specific substances across the membrane. They frequently undergo significant conformational changes to move a substance through the membrane. They are usually highly hydrophobic and aggregate and precipitate in water. They require detergents or nonpolar solvents for extraction, although some of them (beta-barrels) can be also extracted using denaturing agents. The peptide sequence that spans the membrane, or the transmembrane segment, is largely hydrophobic and can be visualized using the hydropathy plot. Depending on the number of transmembrane segments, transmembrane proteins can be classified as single-span (or bitopic) or multi-span (polytopic). Some other integral membrane proteins are called monotopic, meaning that they are also permanently attached to the membrane, but do not pass t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzymes Of Known Structure
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction rat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Membrane Proteins
Membrane proteins are common proteins that are part of, or interact with, biological membranes. Membrane proteins fall into several broad categories depending on their location. Integral membrane proteins are a permanent part of a cell membrane and can either penetrate the membrane (transmembrane) or associate with one or the other side of a membrane ( integral monotopic). Peripheral membrane proteins are transiently associated with the cell membrane. Membrane proteins are common, and medically important—about a third of all human proteins are membrane proteins, and these are targets for more than half of all drugs. Nonetheless, compared to other classes of proteins, determining membrane protein structures remains a challenge in large part due to the difficulty in establishing experimental conditions that can preserve the correct conformation of the protein in isolation from its native environment. Function Membrane proteins perform a variety of functions vital to the surv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Anion Transporter 1
The organic anion transporter 1 (OAT1) also known as solute carrier family 22 member 6 (SLC22A6) is a protein that in humans is encoded by the ''SLC22A6'' gene. It is a member of the organic anion transporter (OAT) family of proteins. OAT1 is a transmembrane protein that is expressed in the brain, the placenta, the eyes, smooth muscles, and the basolateral membrane of proximal tubular cells of the kidneys. It plays a central role in renal organic anion transport. Along with OAT3, OAT1 mediates the uptake of a wide range of relatively small and hydrophilic organic anions from plasma into the cytoplasm of the proximal tubular cells of the kidneys. From there, these substrates are transported into the lumen of the nephrons of the kidneys for excretion. OAT1 homologs have been identified in rats, mice, rabbits, pigs, flounders, and nematodes. Function OAT1 functions as organic anion exchanger. When the uptake of one molecule of an organic anion is transported into a cell by an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Anion-transporting Polypeptide
Members of the Organo Anion Transporter (OAT) Family (organic-anion-transporting polypeptides, OATP) are membrane transport proteins or 'transporters' that mediate the transport of mainly organic anions across the cell membrane. Therefore, OATPs are present in the lipid bilayer of the cell membrane, acting as the cell's gatekeepers. OATPs belong to the Solute Carrier Family (SLC) and the major facilitator superfamily. The generalized transport reactions catalyzed by members of the OAT family are: Anion (in) → Anion (out) Anion1 (in) + Anion2 (out) → Anion1 (out) + Anion2 (in) Function Proteins of the OAT family catalyze the Na+-independent facilitated transport of fairly large amphipathic organic anions (and less frequently neutral or cationic drugs), such as bromosulfobromophthalein, prostaglandins, conjugated and unconjugated bile acids (taurocholate and cholate), steroid conjugates, thyroid hormones, anionic oligopeptides, drugs, toxins and other xenobiotics. One famil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Cation Transport Proteins
An organic cation transport protein mediates the transport of organic cations across the cell membrane. These proteins are members of the solute carrier family, subfamily 22. This family of proteins can also transport zwitterions and anions, though it is a different subfamily of solute carrier proteins than the organic anion transporters. Proteins {, class="wikitable sortable" border="1" , - !Abbreviation!!Protein name!!Location!!Transported solute(s), , Associated disorder(s) , - , , SLC22A1, , Solute carrier family 22 member 1, , Liver, brain (cerebellum), , , , , - , , SLC22A2, , Solute carrier family 22 member 2, , Primarily in kidney, also in brain, , , , , - , , SLC22A3, , Solute carrier family 22 member 3, , Brain and kidney , , Histamine, dopamine, serotonin, norepinephrine, MPP+ , , , - , , SLC22A4, , Solute carrier family 22 member 4, , , , Sodium ion and ergothioneine , , , - , , SLC22A5, , Solute carrier family 22 member 5, , , , , , Primary carnitine d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
