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CYP11A1
Cholesterol side-chain cleavage enzyme is commonly referred to as P450scc, where "scc" is an abbreviation for side-chain cleavage. P450scc is a mitochondrial enzyme that catalyzes conversion of cholesterol to pregnenolone. This is the first reaction in the process of steroidogenesis in all mammalian tissues that specialize in the production of various steroid hormones. P450scc is a member of the cytochrome P450 superfamily of enzymes (family 11, subfamily A, polypeptide 1) and is encoded by the gene. Nomenclature The systematic name of this enzyme class is cholesterol, reduced-adrenal-ferredoxin:oxygen oxidoreductase (side-chain-cleaving). Other names include: * C27-side-chain cleavage enzyme * cholesterol 20-22-desmolase * cholesterol C20-22 desmolase * cholesterol desmolase * cholesterol side-chain cleavage enzyme * cholesterol side-chain-cleaving enzyme * cytochrome P-450scc * desmolase, steroid 20-22 * enzymes, cholesterol side-chain-cleaving * steroid 20-22 desm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adrenodoxin
Adrenal ferredoxin (also adrenodoxin (ADX), adrenodoxin, mitochondrial, hepatoredoxin, ferredoxin-1 (FDX1)) is a protein that in humans is encoded by the ''FDX1'' gene. In addition to the expressed gene at this chromosomal locus (11q22), there are pseudogenes located on chromosomes 20 and 21. Function Adrenodoxin is a small iron-sulfur protein that can accept and carry a single electron. Adrenodoxin functions as an electron transfer protein in the mitochondrial cytochrome P450 systems. The first enzyme in this system is adrenodoxin reductase that carries an FAD. FAD can be reduced by two electrons donated from coenzyme NADPH. These two electrons are transferred one a time to adrenodoxin. Adrenodoxin in return reduces mitochondrial cytochrome P450. This particular oxidation/reduction system is involved in the synthesis of steroid hormones in steroidogenic tissues. In addition, similar systems also function in vitamin D Vitamin D is a group of structurally related, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adrenodoxin Reductase
Adrenodoxin reductase (Enzyme Nomenclature name: adrenodoxin-NADP+ reductase, EC 1.18.1.6), was first isolated from bovine adrenal cortex where it functions as the first enzyme in the mitochondrial P450 systems that catalyze essential steps in steroid hormone biosynthesis. Examination of complete genome sequences revealed that adrenodoxin reductase gene is present in most metazoans and prokaryotes. Nomenclature The name of the enzyme was coined based on its function to reduce a Fe-2S(2 iron, 2 sulfur) electron-transfer protein that was named adrenodoxin. Later, in some studies, the enzyme was also referred to as a "ferredoxin reductase", as adrenodoxin is a ferredoxin. In the human gene nomenclature, the standard name is ferredoxin reductase and the symbol is FDXR, with ADXR specified as a synonym. The assignment of the name "ferredoxin reductase" has been criticized as a misnomer because determination of the structure of adrenodoxin reductase revealed that it is completely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steroidogenic Factor 1
The steroidogenic factor 1 (SF-1) protein is a transcription factor involved in sex determination by controlling the activity of genes related to the reproductive glands or gonads and adrenal glands. This protein is encoded by the ''NR5A1'' gene, a member of the nuclear receptor subfamily, located on the long arm of chromosome 9 at position 33.3. It was originally identified as a regulator of genes encoding cytochrome P450 steroid hydroxylases, however, further roles in endocrine function have since been discovered. Structure The ''NR5A1'' gene encodes a 461-amino acid protein that shares several conserved domains consistent with members of the nuclear receptor subfamily. The N-terminal domain includes two zinc fingers and is responsible for DNA binding via specific recognition of target sequences. Variations of AGGTCA DNA motifs allows SF-1 to interact with the major groove of the DNA helix and monomerically bind. Following binding, trans-activation of target genes depends on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcription Factor
In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription (genetics), transcription of genetics, genetic information from DNA to messenger RNA, by binding to a specific DNA sequence. The function of TFs is to regulate—turn on and off—genes in order to make sure that they are Gene expression, expressed in the desired Cell (biology), cells at the right time and in the right amount throughout the life of the cell and the organism. Groups of TFs function in a coordinated fashion to direct cell division, cell growth, and cell death throughout life; cell migration and organization (body plan) during embryonic development; and intermittently in response to signals from outside the cell, such as a hormone. There are approximately 1600 TFs in the human genome. Transcription factors are members of the proteome as well as regulome. TFs work alone or with other proteins in a complex, by promoting (a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Expression
Gene expression is the process (including its Regulation of gene expression, regulation) by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, proteins or non-coding RNA, and ultimately affect a phenotype. These products are often proteins, but in non-protein-coding genes such as Transfer RNA, transfer RNA (tRNA) and Small nuclear RNA, small nuclear RNA (snRNA), the product is a functional List of RNAs, non-coding RNA. The process of gene expression is used by all known life—eukaryotes (including multicellular organisms), prokaryotes (bacteria and archaea), and viruses—to generate the macromolecule, macromolecular machinery for life. In genetics, gene expression is the most fundamental level at which the genotype gives rise to the phenotype, ''i.e.'' observable trait. The genetic information stored in DNA represents the genotype, whereas the phenotype results from the "interpretation" of that informati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corticotropin
Adrenocorticotropic hormone (ACTH; also adrenocorticotropin, corticotropin) is a polypeptide tropic hormone produced by and secreted by the anterior pituitary gland. It is also used as a medication and diagnostic agent. ACTH is an important component of the hypothalamic-pituitary-adrenal axis and is often produced in response to biological stress (along with its precursor corticotropin-releasing hormone from the hypothalamus). Its principal effects are increased production and release of cortisol and androgens by the zona fasiculata and zona reticularis, respectively. ACTH is also related to the circadian rhythm in many organisms. Deficiency of ACTH is an indicator of secondary adrenal insufficiency (suppressed production of ACTH due to an impairment of the pituitary gland or hypothalamus, cf. hypopituitarism) or tertiary adrenal insufficiency (disease of the hypothalamus, with a decrease in the release of corticotropin releasing hormone (CRH)). Conversely, chronically elev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zona Fasciculata
The ''zona fasciculata'' (sometimes, fascicular or fasciculate zone) constitutes the middle and also the widest zone of the adrenal cortex, sitting directly beneath the ''zona glomerulosa''. Constituent cells are organized into bundles or "fascicles". The ''zona fasciculata'' chiefly produces glucocorticoids (mainly cortisol in humans), which regulate the metabolism of glucose. Glucocorticoid production is stimulated by adrenocorticotropic hormone (ACTH), which is released from the anterior pituitary, especially in times of stress as part of the fight-or-flight response. The ''zona fasciculata'' also generates a small amount of weak androgens (e.g., dehydroepiandrosterone). The main source of androgens will come from the '' zona reticularis'' region. In certain animals such as rodents, the lack of 17alpha-hydroxylase results in the synthesis of corticosterone instead of cortisol. Steroid-producing adrenal tumours and hyperplasia of the ''zona fasciculata'' result in excess ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ternary Complex
A ternary complex is a protein complex containing three different molecules that are bound together. In structural biology, ''ternary complex'' can also be used to describe a crystal containing a protein with two small molecules bound, such as a cofactor and a substrate; or a complex formed between two proteins and a single substrate. In Immunology, ''ternary complex'' can refer to the MHC–peptide–T-cell-receptor complex formed when T cells recognize epitopes of an antigen. Another important example is the ternary complex formed during eukaryotic translation, in which ternary complex composed of eIF2 + GTP + Met-tRNAiMet is formed. A ternary complex can be a complex formed between two substrate molecules and an enzyme. This is seen in multi-substrate enzyme-catalyzed reactions where two substrates and two products can be formed. The ternary complex is an intermediate species in this type of enzyme-catalyzed reaction. An example for a ternary complex is seen in the random-orde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reducing Equivalents
Reduction, reduced, or reduce may refer to: Science and technology Chemistry * Reduction (chemistry), part of a reduction-oxidation (redox) reaction in which atoms have their oxidation state changed. ** Organic redox reaction, a redox reaction that takes place with organic compounds ** Ore reduction: see smelting Computing and algorithms * Reduction (complexity), a transformation of one problem into another problem * Reduction (recursion theory), given sets A and B of natural numbers, is it possible to effectively convert a method for deciding membership in B into a method for deciding membership in A? * Bit Rate Reduction, an audio compression method * Data reduction, simplifying data in order to facilitate analysis * Graph reduction, an efficient version of non-strict evaluation * L-reduction, a transformation of optimization problems which keeps the approximability features * Partial order reduction, a technique for reducing the size of the state-space to be search ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron
The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary charge, elementary electric charge. It is a fundamental particle that comprises the ordinary matter that makes up the universe, along with up quark, up and down quark, down quarks. Electrons are extremely lightweight particles that orbit the positively charged atomic nucleus, nucleus of atoms. Their negative charge is balanced by the positive charge of protons in the nucleus, giving atoms their overall electric charge#Charge neutrality, neutral charge. Ordinary matter is composed of atoms, each consisting of a positively charged nucleus surrounded by a number of orbiting electrons equal to the number of protons. The configuration and energy levels of these orbiting electrons determine the chemical properties of an atom. Electrons are bound to the nucleus to different degrees. The outermost or valence electron, valence electrons are the least tightly bound and are responsible for th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxylation
In chemistry, hydroxylation refers to the installation of a hydroxyl group () into an organic compound. Hydroxylations generate alcohols and phenols, which are very common functional groups. Hydroxylation confers some degree of water-solubility. Hydroxylation of a hydrocarbon is an oxidation, thus a step in degradation. Biological hydroxylation In biochemistry, hydroxylation reactions are often facilitated by enzymes called hydroxylases. These enzymes insert an O atom into a bond. Typical stoichiometries for the hydroxylation of a generic hydrocarbon are these: : : Since itself is a slow and unselective hydroxylating agent, catalysts are required to accelerate the pace of the process and to introduce selectivity. Hydroxylation is often the first step in the degradation of organic compounds in air. Hydroxylation is important in detoxification since it converts lipophilic compounds into water-soluble (hydrophilic) products that are more readily removed by the kidneys or liver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
