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Plasma Gelsolin
Plasma gelsolin (pGSN) is an 83 kDa abundant protein constituent of normal plasma and an important component of the innate immune system. The identification of pGSN in ''Drosophila melanogaster'' and ''C. elegans'' points to an ancient origin early in evolution. Its extraordinary structural conservation reflects its critical regulatory role in multiple essential functions. Its roles include the breakdown of filamentous actin released from dead cells, activation of macrophages, and localization of the inflammatory response. Substantial decreases in plasma levels are observed in acute and chronic infection and injury in both animal models and in humans. Supplementation therapies with recombinant human pGSN have been shown effective in more than 20 animal models. pGSN has a cytoplasmic isoform (cGSN) known to be an actin-binding protein controlling cytoskeletal dynamics. cGSN is expressed from the same gene, and is identical to pGSN except for its lack of a 24 amino acid N-ter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Plasma
Blood plasma is a light amber-colored liquid component of blood in which blood cells are absent, but contains proteins and other constituents of whole blood in suspension. It makes up about 55% of the body's total blood volume. It is the intravascular part of extracellular fluid (all body fluid outside cells). It is mostly water (up to 95% by volume), and contains important dissolved proteins (6–8%; e.g., serum albumins, globulins, and fibrinogen), glucose, clotting factors, electrolytes (, , , , , etc.), hormones, carbon dioxide (plasma being the main medium for excretory product transportation), and oxygen. It plays a vital role in an intravascular osmotic effect that keeps electrolyte concentration balanced and protects the body from infection and other blood-related disorders. Blood plasma is separated from the blood by spinning a vessel of fresh blood containing an anticoagulant in a centrifuge until the blood cells fall to the bottom of the tube. The blood plasma is t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
α-helix
The alpha helix (α-helix) is a common motif in the secondary structure of proteins and is a right hand-helix conformation in which every backbone N−H group hydrogen bonds to the backbone C=O group of the amino acid located four residues earlier along the protein sequence. The alpha helix is also called a classic Pauling–Corey–Branson α-helix. The name 3.613-helix is also used for this type of helix, denoting the average number of residues per helical turn, with 13 atoms being involved in the ring formed by the hydrogen bond. Among types of local structure in proteins, the α-helix is the most extreme and the most predictable from sequence, as well as the most prevalent. Discovery In the early 1930s, William Astbury showed that there were drastic changes in the X-ray fiber diffraction of moist wool or hair fibers upon significant stretching. The data suggested that the unstretched fibers had a coiled molecular structure with a characteristic repeat of ≈. Astb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apolipoprotein H
β2-glycoprotein 1, also known as beta-2 glycoprotein 1 and Apolipoprotein H (Apo-H), is a 38 kDa multifunctional plasma protein that in humans is encoded by the ''APOH'' gene. One of its functions is to bind cardiolipin. When bound, the structure of cardiolipin and β2-GP1 both undergo large changes in structure. Within the structure of Apo-H is a stretch of positively charged amino acids (protein sequence positions 282-287), Lys-Asn-Lys-Glu-Lys-Lys, are involved in phospholipid binding (see image on right). β2-GP1 has a complex involvement in agglutination. It appears to alter adenosine diphosphate (ADP)-mediated agglutination of platelets. Normally, β2-GP1 assumes an anticoagulation activity in serum (by inhibiting coagulation factors); however, changes in blood factors can result in a reversal of that activity. Although previously referred to as apolipoprotein H, it is not present in appreciable quantities in the lipoprotein fractions, so ApoH is therefore thought to be a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma Gelsolin
Plasma gelsolin (pGSN) is an 83 kDa abundant protein constituent of normal plasma and an important component of the innate immune system. The identification of pGSN in ''Drosophila melanogaster'' and ''C. elegans'' points to an ancient origin early in evolution. Its extraordinary structural conservation reflects its critical regulatory role in multiple essential functions. Its roles include the breakdown of filamentous actin released from dead cells, activation of macrophages, and localization of the inflammatory response. Substantial decreases in plasma levels are observed in acute and chronic infection and injury in both animal models and in humans. Supplementation therapies with recombinant human pGSN have been shown effective in more than 20 animal models. pGSN has a cytoplasmic isoform (cGSN) known to be an actin-binding protein controlling cytoskeletal dynamics. cGSN is expressed from the same gene, and is identical to pGSN except for its lack of a 24 amino acid N-ter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium Metabolism
Calcium metabolism is the movement and regulation of calcium ions (Ca2+) ''in'' (via the gut) and ''out'' (via the gut and kidneys) of the body, and ''between'' body compartments: the blood plasma, the extracellular and intracellular fluids, and bone. Bone acts as a calcium storage center for deposits and withdrawals as needed by the blood via continual bone remodeling. An important aspect of calcium metabolism is plasma calcium homeostasis, the regulation of calcium ions in the blood plasma within narrow limits. The level of the calcium in plasma is regulated by the hormones parathyroid hormone (PTH) and calcitonin. PTH is released by the chief cells of the parathyroid glands when the plasma calcium level falls below the normal range in order to raise it; calcitonin is released by the parafollicular cells of the thyroid gland when the plasma level of calcium is above the normal range in order to lower it. Body compartment content Calcium is the most abundant mineral in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amyloid
Amyloids are aggregates of proteins characterised by a Fibril, fibrillar morphology of 7–13 Nanometer, nm in diameter, a beta sheet (β-sheet) Secondary structure of proteins, secondary structure (known as cross-β) and ability to be Staining, stained by particular dyes, such as Congo red. In the human body, amyloids have been linked to the development of various diseases. Pathogenic amyloids form when previously healthy proteins lose their normal Protein structure, structure and physiology, physiological functions (Protein misfolding, misfolding) and form fibrous deposits in amyloid plaques around cells which can disrupt the healthy function of tissues and organs. Such amyloids have been associated with (but not necessarily as the cause of) more than 50 human diseases, known as amyloidosis, and may play a role in some neurodegenerative diseases. Some of these diseases are mainly sporadic and only a few cases are Genetic disorder, familial. Others are only Genetic disorder, fam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hereditary Gelsolin Amyloidosis
Familial Amyloidosis, Finnish Type (FAF), also called hereditary gelsolin amyloidosis and AGel amyloidosis (AGel), is an amyloid condition with a number of associated cutaneous and neurological presentations deriving from the aberrant proteolysis of a mutated form of plasma gelsolin. First described in 1969 by the Finnish ophthalmologist Jouko Meretoja, FAF is uncommon with 400–600 cases described in Finland and 15 elsewhere. Clinical presentation The disorder is primarily associated with eye, skin, and cranial nerve symptoms with the onset of symptoms appearing between the thirties and fifties. The most common characteristic is type II lattice corneal dystrophy with other signs such as polyneuropathy, dermatochalasis, open-angle glaucoma, bilateral progressive facial paralysis, cutis laxa, skin fragility with ecchymosis, facial mask, diffuse hair loss, dry skin, carpal tunnel syndrome, nephrotic syndrome, cardiomyopathy with conduction alterations, and early aging associated wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Point Mutation
A point mutation is a genetic mutation where a single nucleotide base is changed, inserted or deleted from a DNA or RNA sequence of an organism's genome. Point mutations have a variety of effects on the downstream protein product—consequences that are moderately predictable based upon the specifics of the mutation. These consequences can range from no effect (e.g. synonymous mutations) to deleterious effects (e.g. frameshift mutations), with regard to protein production, composition, and function. Causes Point mutations usually take place during DNA replication. DNA replication occurs when one double-stranded DNA molecule creates two single strands of DNA, each of which is a template for the creation of the complementary strand. A single point mutation can change the whole DNA sequence. Changing one purine or pyrimidine may change the amino acid that the nucleotides code for. Point mutations may arise from spontaneous mutations that occur during DNA replication. The rate of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axon
An axon (from Greek ἄξων ''áxōn'', axis), or nerve fiber (or nerve fibre: see spelling differences), is a long, slender projection of a nerve cell, or neuron, in vertebrates, that typically conducts electrical impulses known as action potentials away from the nerve cell body. The function of the axon is to transmit information to different neurons, muscles, and glands. In certain sensory neurons (pseudounipolar neurons), such as those for touch and warmth, the axons are called afferent nerve fibers and the electrical impulse travels along these from the periphery to the cell body and from the cell body to the spinal cord along another branch of the same axon. Axon dysfunction can be the cause of many inherited and acquired neurological disorders that affect both the peripheral and central neurons. Nerve fibers are classed into three typesgroup A nerve fibers, group B nerve fibers, and group C nerve fibers. Groups A and B are myelinated, and group C are unmyelinated. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myelin
Myelin is a lipid-rich material that surrounds nerve cell axons (the nervous system's "wires") to insulate them and increase the rate at which electrical impulses (called action potentials) are passed along the axon. The myelinated axon can be likened to an electrical wire (the axon) with insulating material (myelin) around it. However, unlike the plastic covering on an electrical wire, myelin does not form a single long sheath over the entire length of the axon. Rather, myelin sheaths the nerve in segments: in general, each axon is encased with multiple long myelinated sections with short gaps in between called nodes of Ranvier. Myelin is formed in the central nervous system (CNS; brain, spinal cord and optic nerve) by glial cells called oligodendrocytes and in the peripheral nervous system (PNS) by glial cells called Schwann cells. In the CNS, axons carry electrical signals from one nerve cell body to another. In the PNS, axons carry signals to muscles and glands or from senso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligodendrocytes
Oligodendrocytes (), or oligodendroglia, are a type of neuroglia whose main functions are to provide support and insulation to axons in the central nervous system of jawed vertebrates, equivalent to the function performed by Schwann cells in the peripheral nervous system. Oligodendrocytes do this by creating the myelin sheath. A single oligodendrocyte can extend its processes to 50 axons, wrapping approximately 1 μm of myelin sheath around each axon; Schwann cells, on the other hand, can wrap around only one axon. Each oligodendrocyte forms one segment of myelin for several adjacent axons. Oligodendrocytes are found only in the central nervous system, which comprises the brain and spinal cord. These cells were originally thought to have been produced in the ventral neural tube; however, research now shows oligodendrocytes originate from the ventral ventricular zone of the embryonic spinal cord and possibly have some concentrations in the forebrain. They are the last cell t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Post-translational Modifications
Post-translational modification (PTM) is the covalent and generally enzymatic modification of proteins following protein biosynthesis. This process occurs in the endoplasmic reticulum and the golgi apparatus. Proteins are synthesized by ribosomes translating mRNA into polypeptide chains, which may then undergo PTM to form the mature protein product. PTMs are important components in cell signaling, as for example when prohormones are converted to hormones. Post-translational modifications can occur on the amino acid side chains or at the protein's C- or N- termini. They can extend the chemical repertoire of the 20 standard amino acids by modifying an existing functional group or introducing a new one such as phosphate. Phosphorylation is a highly effective mechanism for regulating the activity of enzymes and is the most common post-translational modification. Many eukaryotic and prokaryotic proteins also have carbohydrate molecules attached to them in a process called glycosylat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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