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Vitamin D-binding Protein
Vitamin D-binding protein (DBP), also/originally known as gc-globulin (group-specific component), is a protein that in humans is encoded by the ''GC'' gene. DBP is genetically the oldest member of the albuminoid family and appeared early in the evolution of vertebrates. Structure Human GC is a glycosylated alpha-globulin, ~58 kDa in size. Its 458 amino acids are coded for by 1690 nucleotides on chromosome 4 (4q11–q13). The primary structure contains 28 cysteine residues forming multiple disulfide bonds. GC contains 3 domains. Domain 1 is composed of 10 alpha helices, domain 2 of 9, and domain 3 of 4. Function Vitamin D-binding protein belongs to the albumin gene family, together with human serum albumin and alpha-fetoprotein. It is a multifunctional protein found in plasma, ascitic fluid, cerebrospinal fluid and on the surface of many cell types. It is able to bind the various forms of vitamin D including ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3), the 25- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metabolic reactions, DNA replication, Cell signaling, responding to stimuli, providing Cytoskeleton, structure to cells and Fibrous protein, organisms, and Intracellular transport, transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the Nucleic acid sequence, nucleotide sequence of their genes, and which usually results in protein folding into a specific Protein structure, 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called pep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcifediol
Calcifediol, also known as calcidiol, 25-hydroxycholecalciferol, or 25-hydroxyvitamin D3 (abbreviated 25(OH)D3), is a form of vitamin D produced in the liver by hydroxylation of vitamin D3 (cholecalciferol) by the enzyme vitamin D 25-hydroxylase. Calcifediol can be further hydroxylated by the enzyme 25(OH)D-1α-hydroxylase, primarily in the kidney, to form calcitriol (1,25-(OH)2D3), which is the active hormonal form of vitamin D. Calcifediol is strongly bound in blood by the vitamin D-binding protein. Measurement of serum calcifediol is the usual test performed to determine a person's vitamin D status, to show vitamin D deficiency or sufficiency. Calcifediol is available as an oral medication in some countries to supplement vitamin D status. Biology Calcifediol is the precursor for calcitriol, the active form of vitamin D. It is synthesized in the liver, by hydroxylation of cholecalciferol (vitamin D3) at the 25-position. This enzymatic 25-hydroxylase reaction is mostly due t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HNF1B
HNF1 homeobox B (hepatocyte nuclear factor 1 homeobox B), also known as HNF1B or transcription factor 2 (TCF2), is a human gene. Function HNF1B encodes hepatocyte nuclear factor 1-beta, a protein of the homeobox-containing basic helix-turn-helix family. The HNF1B protein is believed to form heterodimers with another member of this transcription factor family, HNF1A; depending on the HNF1B isoform, the result may be to activate or inhibit transcription of target genes. Deficiency of HNF1B cause abnormal maternal-Zygote transition and early embryogenesis failure. Mutation of HNF1B that disrupts normal function has been identified as the cause of MODY 5 ( Maturity-Onset of Diabetes, Type 5). A third human transcript variant is believed to exist based on such a variant in the rat: however, to date such an mRNA species has not been isolated. See also * Hepatocyte nuclear factors Hepatocyte nuclear factors (HNFs) are a group of phylogenetically unrelated transcription factors that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HNF1A
HNF1 homeobox A (hepatocyte nuclear factor 1 homeobox A), also known as HNF1A, is a human gene on chromosome 12. It is ubiquitously expressed in many tissues and cell types. The protein encoded by this gene is a transcription factor that is highly expressed in the liver and is involved in the regulation of the expression of several liver-specific genes. Mutations in the ''HNF1A'' gene have been known to cause diabetes. The ''HNF1A'' gene also contains a SNP associated with increased risk of coronary artery disease. Structure Gene The ''HNF1A'' gene resides on chromosome 12 at the band 12q24.2 and contains 10 exons. This gene produces 8 isoforms through alternative splicing. Protein This protein belongs to the HNF1 homeobox family. It contains 3 functional domains: an N-terminal dimerization domain ( residues 1–32), a bipartite DNA-binding motif containing an atypical POU-homeodomain (residues 98–280), and a C-terminal transactivation domain (residues 281–631). T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood
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 is composed of blood cells suspended in blood plasma. Plasma, which constitutes 55% of blood fluid, is mostly water (92% by volume), and contains proteins, glucose, mineral ions, and hormones. The blood cells are mainly red blood cells (erythrocytes), white blood cells (leukocytes), and (in mammals) platelets (thrombocytes). The most abundant cells are red blood cells. These contain hemoglobin, which facilitates oxygen transport by reversibly binding to it, increasing its solubility. Jawed vertebrates have an adaptive immune system, based largely on white blood cells. White blood cells help to resist infections and parasites. Platelets are important in the clotting of blood. Blood is circulated around the body through blood vessels by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatic Parenchymal Cell
A hepatocyte is a cell of the main parenchymal tissue of the liver. Hepatocytes make up 80% of the liver's mass. These cells are involved in: * Protein synthesis * Protein storage * Transformation of carbohydrates * Synthesis of cholesterol, bile salts and phospholipids * Detoxification, modification, and excretion of exogenous and endogenous substances * Initiation of formation and secretion of bile Structure The typical hepatocyte is cubical with sides of 20-30 μm, (in comparison, a human hair has a diameter of 17 to 180 μm).The diameter of human hair ranges from 17 to 181 μm. The typical volume of a hepatocyte is 3.4 x 10−9 cm3. Smooth endoplasmic reticulum is abundant in hepatocytes, in contrast to most other cell types. Microanatomy Hepatocytes display an eosinophilic cytoplasm, reflecting numerous mitochondria, and basophilic stippling due to large amounts of rough endoplasmic reticulum and free ribosomes. Brown lipofuscin granules are also observed (with in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrophage
Macrophages (; abbreviated MPhi, φ, MΦ or MP) are a type of white blood cell of the innate immune system that engulf and digest pathogens, such as cancer cells, microbes, cellular debris and foreign substances, which do not have proteins that are specific to healthy body cells on their surface. This self-protection method can be contrasted with that employed by Natural killer cell, Natural Killer cells. This process of engulfment and digestion is called phagocytosis; it acts to defend the host against infection and injury. Macrophages are found in essentially all tissues, where they patrol for potential pathogens by amoeboid movement. They take various forms (with various names) throughout the body (e.g., histiocytes, Kupffer cells, alveolar macrophages, microglia, and others), but all are part of the mononuclear phagocyte system. Besides phagocytosis, they play a critical role in nonspecific defense (innate immunity) and also help initiate specific defense mechanisms (adapti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrophage Activating Factor
A macrophage-activating factor (MAF) is a lymphokine or other receptor based signal that primes macrophages towards cytotoxicity to tumors, cytokine secretion, or clearance of pathogens. Similar molecules may cause development of an inhibitory, regulatory phenotype. A MAF can also alter the ability of macrophages to present MHC I antigen, participate in Th responses, and/or affect other immune responses. MAFs act typically in combination to produce a specific phenotype. Macrophage activated phenotypes Macrophages inherently display tissue and environment-dependent plasticity. In addition, the phenotypes of the macrophages in a certain environment play a fundamental role in determining the immune activity and response within the tissue. Depending on the combination of MAFs signaling to the macrophage, the macrophage’s activated phenotype becomes one of three major categories: classically activated, wound healing, or regulatory. Regulatory-phenotype macrophages have only recent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gc-MAF
GcMAF (or Gc protein-derived macrophage activating factor) is a protein produced by modification of vitamin D-binding protein. It has been falsely promoted as a treatment for various medical conditions, but claims of its benefits are not supported by evidence. Biochemically, GcMAF results from sequential deglycosylation of the vitamin D-binding protein (the Gc protein), which is naturally promoted by lymphocytes ( B and T cells). The resulting protein may be a macrophage activating factor (MAF). MAFs are lymphokines that control the expression of antigens on the surface of macrophages, and one of their functions is to make macrophages become cytotoxic to tumors. False claims Since around 2008, GcMAF has been promoted as a cure for cancer, HIV, autism and other conditions. Three out of four of the original studies authored by Yamamoto (published between 2007 and 2009) were retracted by the scientific journals in which they were published in 2014, officially due to irregula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcitriol
Calcitriol is a hormone and the active form of vitamin D, normally made in the kidney. It is also known as 1,25-dihydroxycholecalciferol. It binds to and activates the vitamin D receptor in the nucleus of the cell, which then increases the expression of many genes. Calcitriol increases blood Calcium in biology, calcium mainly by increasing the uptake of calcium from the intestines. It can be given as a medication for the treatment of hypocalcemia, low blood calcium and hyperparathyroidism due to kidney disease, low blood calcium due to hypoparathyroidism, osteoporosis, osteomalacia, and familial hypophosphatemia, and can be taken by mouth or by intravenous, injection into a vein. Excessive amounts or intake can result in weakness, headache, nausea, constipation, urinary tract infections, and abdominal pain. Serious side effects may include high blood calcium and anaphylaxis. Calcitriol was identified as the active form of vitamin D in 1971 and the drug was approved for medic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cholecalciferol
Cholecalciferol, also known as vitamin D3, colecalciferol or calciol, is a type of vitamin D that is produced by the skin when exposed to UV light, UVB light; it is found in certain foods and can be taken as a dietary supplement. Cholecalciferol is synthesised in the skin following sunlight exposure. It is then converted in the liver to calcifediol (25-hydroxycholecalciferol D), which is further converted in the kidney to calcitriol (1,25-dihydroxycholecalciferol D). One of calcitriol's most important functions is to promote calcium uptake by the intestines. Cholecalciferol is present in food such as fatty fish, beef liver, eggs, and cheese. In some countries, cholecalciferol is also added to products like plants, cow milk, fruit juice, yogurt, and margarine. Cholecalciferol can be taken orally as a dietary supplement to prevent vitamin D deficiency or as a medication to treat associated diseases, including rickets. It is also used in the management of familial hypophosphatem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and non-coding genes. During gene expression (the synthesis of Gene product, RNA or protein from a gene), DNA is first transcription (biology), copied into RNA. RNA can be non-coding RNA, directly functional or be the intermediate protein biosynthesis, template for the synthesis of a protein. The transmission of genes to an organism's offspring, is the basis of the inheritance of phenotypic traits from one generation to the next. These genes make up different DNA sequences, together called a genotype, that is specific to every given individual, within the gene pool of the population (biology), population of a given species. The genotype, along with environmental and developmental factors, ultimately determines the phenotype ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
