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Apolipoprotein C
In the field of molecular biology, apolipoprotein C is a family of four low molecular weight apolipoproteins, designated as C-I, C-II, C-III, and C-IV. These are surface components of chylomicrons, VLDL, and HDL. When an organism is in the fasting state, the C apolipoproteins are mainly associated with HDL. But during absorption of dietary fat, the C apolipoproteins preferentially redistribute to the surface of the triglyceride A triglyceride (from '' tri-'' and '' glyceride''; also TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids. Triglycerides are the main constituents of body fat in humans and other vertebrates ...-rich chylomicrons and VLDL. References Apolipoproteins {{protein-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Biology
Molecular biology is a branch of biology that seeks to understand the molecule, molecular basis of biological activity in and between Cell (biology), cells, including biomolecule, biomolecular synthesis, modification, mechanisms, and interactions. Though cells and other microscopic structures had been observed in living organisms as early as the 18th century, a detailed understanding of the mechanisms and interactions governing their behavior did not emerge until the 20th century, when technologies used in physics and chemistry had advanced sufficiently to permit their application in the biological sciences. The term 'molecular biology' was first used in 1945 by the English physicist William Astbury, who described it as an approach focused on discerning the underpinnings of biological phenomena—i.e. uncovering the physical and chemical structures and properties of biological molecules, as well as their interactions with other molecules and how these interactions explain observ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apolipoprotein
Apolipoproteins are proteins that bind lipids (oil-soluble substances such as fats, cholesterol and fat soluble vitamins) to form lipoproteins. They transport lipids in blood, cerebrospinal fluid and lymph. The lipid components of lipoproteins are insoluble in water. However, because of their detergent-like ( amphipathic) properties, apolipoproteins and other amphipathic molecules (such as phospholipids) can surround the lipids, creating a lipoprotein particle that is itself water-soluble, and can thus be carried through body fluids (i.e., blood, lymph). In addition to stabilizing lipoprotein structure and solubilizing the lipid component, apolipoproteins interact with lipoprotein receptors and lipid transport proteins, thereby participating in lipoprotein uptake and clearance. They also serve as enzyme cofactors for specific enzymes involved in the metabolism of lipoproteins. Apolipoproteins are also exploited by hepatitis C virus (HCV) to enable virus entry, assembly, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apolipoprotein C-I
Apolipoprotein C-I is a protein component of lipoproteins that in humans is encoded by the ''APOC1'' gene. Function The protein encoded by this gene is a member of the apolipoprotein C family. This gene is expressed primarily in the liver, and it is activated when monocytes differentiate into macrophages. Alternatively spliced transcript variants have been found for this gene, but the biological validity of some variants has not been determined. Apolipoprotein C-I has a length of 57 amino acids normally found in plasma and responsible for the activation of esterified lecithin cholesterol with an important role in the exchange of esterified cholesterol between lipoproteins and in removal of cholesterol from tissues. Its main function is inhibition of cholesteryl ester transfer protein (CETP), probably by altering the electric charge of HDL molecules. During fasting (like other apolipoprotein C), it is found primarily within HDL, while after a meal it is found on the surfac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apolipoprotein C-II
Apolipoprotein C-II (Apo-CII, or Apoc-II), or apolipoprotein C2 is a protein that in humans is encoded by the gene. The protein encoded by this gene is secreted in plasma, where it is a component of very low density lipoproteins and chylomicrons. This protein activates the enzyme lipoprotein lipase in capillaries, which hydrolyzes triglycerides and thus provides free fatty acids and glycerols for cells. Mutations in this gene cause hyperlipoproteinemia type IB, characterized by xanthomas, pancreatitis, and hepatosplenomegaly, but no increased risk for atherosclerosis Atherosclerosis is a pattern of the disease arteriosclerosis, characterized by development of abnormalities called lesions in walls of arteries. This is a chronic inflammatory disease involving many different cell types and is driven by eleva .... Lab tests will show elevated blood levels of triglycerides, cholesterol, and chylomicrons Interactive pathway map See also * Apolipoprotein C References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apolipoprotein C-III
Apolipoprotein C-III also known as apo-CIII, and apolipoprotein C3, is a protein that in humans is encoded by the ''APOC3'' gene. Apo-CIII is secreted by the liver as well as the small intestine, and is found on triglyceride-rich lipoproteins such as chylomicrons, very low density lipoprotein (VLDL), and remnant cholesterol. Structure ApoC-III is a relatively small protein containing 79 amino acids that can be glycosylated at threonine-74. The most abundant glycoforms are characterized by an ''O''-linked disaccharide galactose linked to ''N''-acetylgalactosamine (Gal–GalNAc), further modified with up to two sialic acid residues. Less abundant glycoforms are characterized by more complex and fucosylated glycan moieties. Function APOC3 inhibits lipoprotein lipase and hepatic lipase; it is thought to inhibit hepatic uptake of triglyceride-rich particles. The '' APOA1'', ''APOC3'' and '' APOA4'' genes are closely linked in both rat and human genomes. The A-I and A-IV gene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apolipoprotein C-IV
Apolipoprotein C-IV, also known as apolipoprotein C4, is a protein that in humans is encoded by the ''APOC4'' gene. Function ''APOC4'' is a member of the apolipoprotein C In the field of molecular biology, apolipoprotein C is a family of four low molecular weight apolipoproteins, designated as C-I, C-II, C-III, and C-IV. These are surface components of chylomicrons, VLDL, and HDL. When an organism is in the fas ... gene family. It is expressed in the liver and has a predicted protein structure characteristic of the other genes in this family. ''APOC4'' is a 3.3-kb gene consisting of 3 exons and 2 introns; it is located 0.5 kb 5' to the ''APOC2'' gene. References External links * Further reading * * * * * * * * * * * * * * * * * * * Apolipoproteins {{gene-19-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chylomicron
Chylomicrons (from the Greek χυλός, chylos, meaning ''juice'' (of plants or animals), and micron, meaning ''small''), also known as ultra low-density lipoproteins (ULDL), are lipoprotein particles that consist of triglycerides (85–92%), phospholipids (6–12%), cholesterol (1–3%), and proteins (1–2%). They transport dietary lipids, such as fats and cholesterol, from the intestines to other locations in the body, within the water-based solution of the bloodstream. ULDLs are one of the five major groups lipoproteins are divided into based on their density. A protein specific to chylomicrons is ApoB48. There is an inverse relationship in the density and size of lipoprotein particles: fats have a lower density than water or smaller protein molecules, and the larger particles have a higher ratio of internal fat molecules with respect to the outer emulsifying protein molecules in the shell. ULDLs, if in the region of 1,000 nm or more, are the only lipoprotein particl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Very Low-density Lipoprotein
Very-low-density lipoprotein (VLDL), density relative to extracellular water, is a type of lipoprotein made by the liver. VLDL is one of the five major groups of lipoproteins (chylomicrons, VLDL, intermediate-density lipoprotein, LDL, low-density lipoprotein, high-density lipoprotein) that enable fats and cholesterol to move within the water-based solution of the bloodstream. VLDL is assembled in the liver from triglycerides, cholesterol, and apolipoproteins. VLDL is converted in the bloodstream to low-density lipoprotein (LDL) and intermediate-density lipoprotein (IDL). VLDL particles have a diameter of 30–80 nanometers (nm). VLDL transports endogeny, endogenous products, whereas chylomicrons transport exogenous (dietary) products. In the early 2010s both the lipid composition and protein composition of this lipoprotein were characterised in great detail. Physical properties Very-low-density lipoprotein size is variable, with diameters ranging from approximately 35 to 70&nbs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-density Lipoprotein
High-density lipoprotein (HDL) is one of the five major groups of lipoproteins. Lipoproteins are complex particles composed of multiple proteins which transport all fat molecules (lipids) around the body within the water outside cells. They are typically composed of 80–100 proteins per particle (organized by one, two or three ApoA). HDL particles enlarge while circulating in the blood, aggregating more fat molecules and transporting up to hundreds of fat molecules per particle. HDL particles are commonly referred to as "good cholesterol", because they transport fat molecules out of artery walls, reduce macrophage accumulation, and thus help prevent or even regress atherosclerosis. Overview Lipoproteins are divided into five subgroups, by density/size (an inverse relationship), which also correlates with function and incidence of cardiovascular events. Unlike the larger lipoprotein particles, which deliver fat molecules to cells, HDL particles remove fat molecules from cells. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triglyceride
A triglyceride (from '' tri-'' and '' glyceride''; also TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids. Triglycerides are the main constituents of body fat in humans and other vertebrates as well as vegetable fat. They are also present in the blood to enable the bidirectional transference of adipose fat and blood glucose from the liver and are a major component of human skin oils. Many types of triglycerides exist. One specific classification focuses on saturated and unsaturated types. Saturated fats have ''no'' C=C groups; unsaturated fats feature one or more C=C groups. Unsaturated fats tend to have a lower melting point than saturated analogues; as a result, they are often liquid at room temperature. Chemical structure The three fatty acids substituents can be the same, but they are usually different. The positions of the three fatty acids are specified using stereospecific numbering as sn-1, sn-2, and sn- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
