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Hyodeoxycholic Acid
Hyodeoxycholic acid, also known as 3α,6α-Dihydroxy-5β-cholan-24-oic acid or HDCA, is a secondary bile acid, one of the metabolic byproducts of intestinal bacteria. It differs from deoxycholic acid in that the 6α-hydroxyl is in the 12 position in the former. The 6α-hydroxyl group makes HDCA a hydrophilic acid, a property it shares with hyocholic acid. HDCA is present in mammalian species in different proportions. It is the main acid constituent of hog bile, and for this reason it was used industrially as precursor for steroid synthesis before total synthesis became practical. Metabolism In rat intestinal microflora hyodeoxycholic acid is produced by a Gram-positive rod—termed HDCA-1—from several isomers of hyocholic acid and muricholic acid. In pigs with a normal gastrointestinal flora the majority of hyodeoxycholic acid found in bile is of secondary nature, but a small amount was also found in germ free pigs, which supports the hypothesis that HDCA may be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bile Acid
Bile acids are steroid acids found predominantly in the bile of mammals and other vertebrates. Diverse bile acids are synthesized in the liver. Bile acids are conjugated with taurine or glycine residues to give anions called bile salts. Primary bile acids are those synthesized by the liver. Secondary bile acids result from bacterial actions in the colon (anatomy), colon. In humans, taurocholic acid and glycocholic acid (derivatives of cholic acid) and taurochenodeoxycholic acid and glycochenodeoxycholic acid (derivatives of chenodeoxycholic acid) are the major bile salts. They are roughly equal in concentration. The salts of their 7-alpha-dehydroxylated derivatives, deoxycholic acid and lithocholic acid, are also found, with derivatives of cholic, chenodeoxycholic and deoxycholic acids accounting for over 90% of human biliary bile acids. Bile acids comprise about 80% of the organic compounds in bile (others are phospholipids and cholesterol). An increased secretion of bile acids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucuronidation
Glucuronidation is often involved in drug metabolism of substances such as drugs, pollutants, bilirubin, androgens, estrogens, mineralocorticoids, glucocorticoids, fatty acid derivatives, retinoids, and bile acids. These linkages involve glycosidic bonds. Mechanism Glucuronidation consists of transfer of the glucuronic acid component of uridine diphosphate glucuronic acid to a substrate by any of several types of UDP-glucuronosyltransferase. UDP-glucuronic acid (glucuronic acid linked via a glycosidic bond to uridine diphosphate) is an intermediate in the process and is formed in the liver. One example is the N-glucuronidation of an aromatic amine, 4-aminobiphenyl, by UGT1A4 or UGT1A9 from human, rat, or mouse liver. : The substances resulting from glucuronidation are known as glucuronides (or glucuronosides) and are typically much more water-soluble than the non-glucuronic acid-containing substances from which they were originally synthesised. The human body uses glucuronidat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biochem
Biochemistry or biological chemistry is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology and metabolism. Over the last decades of the 20th century, biochemistry has become successful at explaining living processes through these three disciplines. Almost all areas of the life sciences are being uncovered and developed through biochemical methodology and research. Voet (2005), p. 3. Biochemistry focuses on understanding the chemical basis which allows biological molecules to give rise to the processes that occur within living cells and between cells,Karp (2009), p. 2. in turn relating greatly to the understanding of tissues and organs, as well as organism structure and function.Miller (2012). p. 62. Biochemistry is closely related to molecular biology, which is the study of the molecular mechanisms of biological phenomena.A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apoptosis
Apoptosis (from grc, ἀπόπτωσις, apóptōsis, 'falling off') is a form of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes (morphology) and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, DNA fragmentation, and mRNA decay. The average adult human loses between 50 and 70 billion cells each day due to apoptosis. For an average human child between eight and fourteen years old, approximately twenty to thirty billion cells die per day. In contrast to necrosis, which is a form of traumatic cell death that results from acute cellular injury, apoptosis is a highly regulated and controlled process that confers advantages during an organism's life cycle. For example, the separation of fingers and toes in a developing human embryo occurs because cells between the digits undergo apoptosis. Unlike necrosis, apoptosis produces cell fragments called apoptotic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colon Cancer
Colorectal cancer (CRC), also known as bowel cancer, colon cancer, or rectal cancer, is the development of cancer from the colon or rectum (parts of the large intestine). Signs and symptoms may include blood in the stool, a change in bowel movements, weight loss, and fatigue. Most colorectal cancers are due to old age and lifestyle factors, with only a small number of cases due to underlying genetic disorders. Risk factors include diet, obesity, smoking, and lack of physical activity. Dietary factors that increase the risk include red meat, processed meat, and alcohol. Another risk factor is inflammatory bowel disease, which includes Crohn's disease and ulcerative colitis. Some of the inherited genetic disorders that can cause colorectal cancer include familial adenomatous polyposis and hereditary non-polyposis colon cancer; however, these represent less than 5% of cases. It typically starts as a benign tumor, often in the form of a polyp, which over time becomes cancerous. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FEBS J
''The FEBS Journal'' is a biweekly peer-reviewed scientific journal published by John Wiley & Sons on behalf of the Federation of European Biochemical Societies. It covers research on all aspects of biochemistry, molecular biology, cell biology, and the molecular bases of disease. The editor-in-chief is Seamus Martin (Trinity College Dublin), who took over from Richard Perham (University of Cambridge) in 2014. Content is available for free 1 year after publication, except review content, which is available immediately. The journal also publishes special and virtual issues focusing on a specific theme. Since 2021, the journal has given an annual award, "The FEBS Journal Richard Perham Prize", for an outstanding research paper published in the journal. The winners receive a €5,000 cash prize (to be divided equally between the first and last authors) and the senior author of the study is invited to give a talk at the FEBS Annual Congress. The journal also gives more frequent post ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Substrate Specificity
Chemical specificity is the ability of binding site of a macromolecule (such as a protein) to bind specific ligands. The fewer ligands a protein can bind, the greater its specificity. Specificity describes the strength of binding between a given protein and ligand. This relationship can be described by a dissociation constant, which characterizes the balance between bound and unbound states for the protein-ligand system. In the context of a single enzyme and a pair of binding molecules, the two ligands can be compared as stronger or weaker ligands (for the enzyme) on the basis of their dissociation constants. (A lower value corresponds to a stronger binding.) Specificity for a set of ligands is unrelated to the ability of an enzyme to catalyze a given reaction, with the ligand as a substrate. If a given enzyme has a high chemical specificity, this means that the set of ligands to which it binds is limited, such that neither binding events nor catalysis can occur at an appreciab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoforms
A protein isoform, or "protein variant", is a member of a set of highly similar proteins that originate from a single gene or gene family and are the result of genetic differences. While many perform the same or similar biological roles, some isoforms have unique functions. A set of protein isoforms may be formed from alternative splicings, variable promoter usage, or other post-transcriptional modifications of a single gene; post-translational modifications are generally not considered. (For that, see Proteoforms.) Through RNA splicing mechanisms, mRNA has the ability to select different protein-coding segments ( exons) of a gene, or even different parts of exons from RNA to form different mRNA sequences. Each unique sequence produces a specific form of a protein. The discovery of isoforms could explain the discrepancy between the small number of protein coding regions genes revealed by the human genome project and the large diversity of proteins seen in an organism: different ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UGT2B7
UGT2B7 (UDP-Glucuronosyltransferase-2B7) is a phase II metabolism isoenzyme found to be active in the liver, kidneys, epithelial cells of the lower gastrointestinal tract and also has been reported in the brain. In humans, UDP-Glucuronosyltransferase-2B7 is encoded by the ''UGT2B7'' gene. Function The UGTs serve a major role in the conjugation and subsequent elimination of potentially toxic xenobiotics and endogenous compounds. UGT2B7 has unique specificity for 3,4-catechol estrogens and estriol, suggesting that it may play an important role in regulating the level and activity of these potent estrogen metabolites. This enzyme is located on the endoplasmic reticulum and nuclear membranes of cells. Its function is to catalyse the conjugation of a wide variety of lipophilic aglycon substrates with glucuronic acid, using uridine diphosphate glucuronic acid. Together with UGT2B4, UGT2B7 is capable of glucosidation of hyodesoxycholic acid in the liver, but, unlike the 2B4 isofor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UGT2B4
UDP glucuronosyltransferase 2 family, polypeptide B4, also known as UGT2B4, is an enzyme that in humans is encoded by the ''UGT2B4'' gene. Function UGT2B4 is mainly involved in the glucuronidation of hyodeoxycholic acid, a bile acid, and catechol-estrogens, such as 17-epiestriol and 4-hydroxy-estrone. The expression of the UGT2B4 enzyme is upregulated by the farnesoid X receptor (FXR), a nuclear receptor In the field of molecular biology, nuclear receptors are a class of proteins responsible for sensing steroids, thyroid hormones, vitamins, and certain other molecules. These receptors work with other proteins to regulate the expression of speci ... which is activated by bile acids. These same bile acids are substrates for the UGT2B4 enzyme. Hence upregulation of UGT2B4 by activated FXR provides a mechanism for the detection, conjugation and subsequent elimination of toxic bile acids. References Further reading * * * * * * * * * * * * * * * * * * * {{gene-4-s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UDP-glucuronosyltransferase
Uridine 5'-diphospho-glucuronosyltransferase ( UDP-glucuronosyltransferase, UGT) is a microsomal glycosyltransferase () that catalyzes the transfer of the glucuronic acid component of UDP-glucuronic acid to a small hydrophobic molecule. This is a glucuronidation reaction. ''Alternative names:'' *glucuronyltransferase *UDP-glucuronyl transferase *UDP-GT Function Glucuronosyltransferases are responsible for the process of glucuronidation, a major part of phase II metabolism. Arguably the most important of the Phase II (conjugative) enzymes, UGTs have been the subject of increasing scientific inquiry since the mid-to-late 1990s. The reaction catalyzed by the UGT enzyme involves the addition of a glucuronic acid moiety to xenobiotics and is the most important pathway for the human body's elimination of the most frequently prescribed drugs. It is also the major pathway for foreign chemical (dietary, environmental, pharmaceutical) removal for most drugs, dietary substances, toxins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chenodeoxycholic Acid
Chenodeoxycholic acid (CDCA; also known as chenodesoxycholic acid, chenocholic acid and 3α,7α-dihydroxy-5β-cholan-24-oic acid) is a bile acid. Salts of this carboxylic acid are called chenodeoxycholates. Chenodeoxycholic acid is one of the main bile acids. It was first isolated from the bile of the domestic goose, which gives it the "cheno" portion of its name (Greek: χήν = goose). Structure Chenodeoxycholic acid and cholic acid are the two primary bile acids in humans. Chenodeoxycholic acid has two hydroxyl groups and is modified with the addition of another hydroxyl group to produce cholic acid. Some other mammals have muricholic acid or deoxycholic acid rather than chenodeoxycholic acid. It occurs as a white crystalline substance insoluble in water but soluble in alcohol and acetic acid, with melting point at 165–167 °C. Biosynthesis and function Chenodeoxycholic acid is synthesized in the liver from cholesterol via several enzymatic steps. Like other bile a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
