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Bacterial Lipoprotein
A proteolipid is a protein covalently linked to lipid molecules, which can be fatty acids, isoprenoids or sterols. The process of such a linkage is known as protein lipidation, and falls into the wider category of acylation and post-translational modification. Proteolipids are abundant in brain tissue, and are also present in many other animal and plant tissues. They include ghrelin, a peptide hormone associated with feeding. Many proteolipids have bound fatty acid chains, which often provide an interface for interacting with biological membranes and act as lipidons that direct proteins to specific zones. Proteolipids were discovered serendipitously in 1951 by Jordi Folch Pi and Marjorie Lees while extracting sulfatides from brain lipids. They are not to be confused with lipoproteins, a kind of spherical assembly made up of many molecules of lipids and some apolipoproteins. Structure Depending on the type of fatty acid attached to the protein, a proteolipid can often con ... [...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] |
Palmitoyl Group
In molecular biology, palmitoylation is the covalent attachment of fatty acids, such as palmitic acid, to cysteine (''S''-palmitoylation) and less frequently to serine and threonine (''O''-palmitoylation) residues of proteins, which are typically membrane proteins. The precise function of palmitoylation depends on the particular protein being considered. Palmitoylation enhances the hydrophobicity of proteins and contributes to their membrane association. Palmitoylation also appears to play a significant role in subcellular trafficking of proteins between membrane compartments, as well as in modulating protein–protein interactions. In contrast to prenylation and myristoylation, palmitoylation is usually reversible (because the bond between palmitic acid and protein is often a thioester bond). The reverse reaction in mammalian cells is catalyzed by acyl-protein thioesterases (APTs) in the cytosol and palmitoyl protein thioesterases in lysosomes. Because palmitoylation is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receptor Affinity
In chemistry, biochemistry, and pharmacology, a dissociation constant (''K''D) is a specific type of equilibrium constant that measures the propensity of a larger object to separate (dissociate) reversibly into smaller components, as when a Complex (chemistry), complex falls apart into its component molecules, or when a salt (chemistry), salt splits up into its component ions. The dissociation constant is the multiplicative inverse, inverse of the association constant. In the special case of salts, the dissociation constant can also be called an ionization constant. For a general reaction: : A_\mathit B_\mathit \mathit A + \mathit B in which a complex \ce_x \ce_y breaks down into ''x'' A subunits and ''y'' B subunits, the dissociation constant is defined as : K_\mathrm = \frac where [A], [B], and [A''x'' B''y''] are the equilibrium concentrations of A, B, and the complex A''x'' B''y'', respectively. One reason for the popularity of the dissociat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioactive Peptides , a terrarium/vivarium which includes a population of invertebrates and microbes to process animal waste
{{disambig ...
Bioactive may refer to: *Biological activity, the effect of a drug or compound on living matter *Bioactive compounds, a compound that has an effect on a living organism, tissue /cell *Bioactive glass,a group of surface reactive glass-ceramic biomaterials used as implanted devices in the human body to repair and replace diseased or damaged bones * Bioactive paper, a paper-based sensor that can identify various contaminants in food and water *Bioactive terrarium A bioactive terrarium (or vivarium) is a terrarium for housing one or more terrestrial animal species that includes live plants and populations of small invertebrates and microorganisms to consume and break down the waste products of the primary s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphiphilic Surfactants
In chemistry, an amphiphile (), or amphipath, is a chemical compound possessing both hydrophilic (''water-loving'', polar) and lipophilic (''fat-loving'', nonpolar) properties. Such a compound is called amphiphilic or amphipathic. Amphiphilic compounds include surfactants and detergents. The phospholipid amphiphiles are the major structural component of cell membranes. Amphiphiles are the basis for a number of areas of research in chemistry and biochemistry, notably that of lipid polymorphism. Organic compounds containing hydrophilic groups at both ends of the molecule are called bolaamphiphilic. The micelles they form in the aggregate are prolate. Structure The lipophilic group is typically a large hydrocarbon moiety, such as a long chain of the form CH3(CH2)n, with n > 4. The hydrophilic group falls into one of the following categories: # charged groups #* anionic. Examples, with the lipophilic part of the molecule represented by ''R'', are: #** carboxylates: RCO2− #** su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peptide Amphiphile
Peptide amphiphiles (PAs) are peptide-based molecules that self-assemble into supramolecular nanostructures including; spherical micelles, twisted ribbons, and high-aspect-ratio nanofibers. A peptide amphiphile typically comprises a hydrophilic peptide sequence attached to a lipid tail, i.e. a hydrophobic alkyl chain with 10 to 16 carbons. Therefore, they can be considered a type of lipopeptide. A special type of PA, is constituted by alternating charged and neutral residues, in a repeated pattern, such as RADA16-I. The PAs were developed in the 1990s and the early 2000s and could be used in various medical areas including: nanocarriers, nanodrugs, and imaging agents. However, perhaps their main potential is in regenerative medicine to culture and deliver cells and growth factors. History Peptide amphiphiles were developed in the 1990s. They were first described by the group of Matthew Tirrell in 1995. These first reported PA molecules were composed of two domains: one of lipophi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S-palmitoylation
In molecular biology, palmitoylation is the covalent attachment of fatty acids, such as palmitic acid, to cysteine (''S''-palmitoylation) and less frequently to serine and threonine (''O''-palmitoylation) residues of proteins, which are typically membrane proteins. The precise function of palmitoylation depends on the particular protein being considered. Palmitoylation enhances the hydrophobicity of proteins and contributes to their membrane association. Palmitoylation also appears to play a significant role in subcellular trafficking of proteins between membrane compartments, as well as in modulating protein–protein interactions. In contrast to prenylation and myristoylation, palmitoylation is usually reversible (because the bond between palmitic acid and protein is often a thioester bond). The reverse reaction in mammalian cells is catalyzed by acyl-protein thioesterases (APTs) in the cytosol and palmitoyl protein thioesterases in lysosomes. Because palmitoylation is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myristoylation
Myristoylation is a lipidation modification where a myristoyl group, derived from myristic acid, is covalently attached by an amide bond to the alpha-amino group of an ''N''-terminal glycine residue. Myristic acid is a 14-carbon saturated fatty acid (14:0) with the systematic name of ''n''-tetradecanoic acid. This modification can be added either co-translationally or post-translationally. ''N''-myristoyltransferase (NMT) catalyzes the myristic acid addition reaction in the cytoplasm of cells. This lipidation event is the most common type of fatty acylation and is present in many organisms, including animals, plants, fungi, protozoans and viruses. Myristoylation allows for weak protein–protein and protein–lipid interactions and plays an essential role in membrane targeting, protein–protein interactions and functions widely in a variety of signal transduction pathways. Discovery In 1982, Koiti Titani's lab identified an "''N''-terminal blocking group" on the catal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prenylation
Prenylation (also known as isoprenylation or lipidation) is the addition of hydrophobic molecules to a protein or a biomolecule. It is usually assumed that prenyl groups (3-methylbut-2-en-1-yl) facilitate attachment to cell membranes, similar to lipid anchors like the GPI anchor, though direct evidence of this has not been observed. Prenyl groups (also called isoprenyl groups, having one hydrogen atom more than isoprene) have been shown to be important for protein–protein binding through specialized prenyl-binding domains. Protein prenylation Protein prenylation involves the transfer of either a farnesyl or a geranylgeranyl moiety to C-terminal cysteine(s) of the target protein. There are three enzymes that carry out prenylation in the cell, farnesyl transferase, Caax protease and geranylgeranyl transferase I. Farnesylation is a type of prenylation, a post-translational modification of proteins by which an isoprenyl group is added to a cysteine residue. It is an important ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cysteine
Cysteine (; symbol Cys or C) is a semiessential proteinogenic amino acid with the chemical formula, formula . The thiol side chain in cysteine enables the formation of Disulfide, disulfide bonds, and often participates in enzymatic reactions as a nucleophile. Cysteine is chiral, but both D and L-cysteine are found in nature. LCysteine is a protein monomer in all biota, and D-cysteine acts as a signaling molecule in mammalian nervous systems. Cysteine is named after its discovery in urine, which comes from the urinary bladder or cyst, from Ancient Greek, Greek κύστις ''kýstis'', "bladder". The thiol is susceptible to oxidation to give the disulfide bond, disulfide derivative cystine, which serves an important structural role in many proteins. In this case, the symbol Cyx is sometimes used. The deprotonated form can generally be described by the symbol Cym as well. When used as a food additive, cysteine has the E number E920. Cysteine is Genetic code, encoded by the codo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palmitoylation
In molecular biology, palmitoylation is the covalent attachment of fatty acids, such as palmitic acid, to cysteine (''S''-palmitoylation) and less frequently to serine and threonine (''O''-palmitoylation) residues of proteins, which are typically membrane proteins. The precise function of palmitoylation depends on the particular protein being considered. Palmitoylation enhances the hydrophobicity of proteins and contributes to their membrane association. Palmitoylation also appears to play a significant role in subcellular trafficking of proteins between membrane compartments, as well as in modulating protein–protein interactions. In contrast to prenylation and myristoylation, palmitoylation is usually reversible (because the bond between palmitic acid and protein is often a thioester bond). The reverse reaction in mammalian cells is catalyzed by acyl-protein thioesterases (APTs) in the cytosol and palmitoyl protein thioesterases in lysosomes. Because palmitoylation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
