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PPT2
Lysosomal thioesterase PPT2 (PPT-2), also known as S-thioesterase G14, is an enzyme that in humans is encoded by the ''PPT2'' gene. Function This gene encodes a member of the palmitoyl protein thioesterase family. The encoded glycosylated lysosomal protein has palmitoyl-CoA hydrolase activity in vitro, but does not hydrolyze palmitate from cysteine Cysteine (symbol Cys or C; ) is a semiessential proteinogenic amino acid with the formula . The thiol side chain in cysteine often participates in enzymatic reactions as a nucleophile. When present as a deprotonated catalytic residue, sometime ... residues in proteins. References Further reading * * * * * * * * * * * * * * * * * EC 3.1.2 {{gene-6-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palmitoyl Protein Thioesterase
Palmitoyl protein hydrolase/thioesterases is an enzyme (EC 3.1.2.22) that removes thioester-linked fatty acyl groups such as palmitate from modified cysteine residues in proteins or peptides during lysosomal degradation. It catalyzes the reaction :palmitoyl rotein+ H2O \rightleftharpoons palmitate + protein This enzyme belongs to the family of hydrolases, specifically those acting on thioester bonds. The systematic name is palmitoyl roteinhydrolase. Other names in common use include palmitoyl-protein thioesterase, and palmitoyl-(protein) hydrolase. This enzyme participates in fatty acid elongation in mitochondria. Neuronal ceroid lipofuscinoses (NCL) represent a group of encephalopathies that occur in 1 in 12,500 children. Mutations in the palmitoyl protein thioesterase gene causing infantile neuronal ceroid lipofuscinosis. The most common mutation results in intracellular accumulation of the polypeptide and undetectable enzyme activity in the brain. Direct sequencing of c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and 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 noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycosylation
Glycosylation is the reaction in which a carbohydrate (or ' glycan'), i.e. a glycosyl donor, is attached to a hydroxyl or other functional group of another molecule (a glycosyl acceptor) in order to form a glycoconjugate. In biology (but not always in chemistry), glycosylation usually refers to an enzyme-catalysed reaction, whereas glycation (also 'non-enzymatic glycation' and 'non-enzymatic glycosylation') may refer to a non-enzymatic reaction (though in practice, 'glycation' often refers more specifically to Maillard-type reactions). Glycosylation is a form of co-translational and post-translational modification. Glycans serve a variety of structural and functional roles in membrane and secreted proteins. The majority of proteins synthesized in the rough endoplasmic reticulum undergo glycosylation. Glycosylation is also present in the cytoplasm and nucleus as the ''O''-GlcNAc modification. Aglycosylation is a feature of engineered antibodies to bypass glycosylation. Five clas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysosome
A lysosome () is a membrane-bound organelle found in many animal cells. They are spherical vesicles that contain hydrolytic enzymes that can break down many kinds of biomolecules. A lysosome has a specific composition, of both its membrane proteins, and its lumenal proteins. The lumen's pH (~4.5–5.0) is optimal for the enzymes involved in hydrolysis, analogous to the activity of the stomach. Besides degradation of polymers, the lysosome is involved in various cell processes, including secretion, plasma membrane repair, apoptosis, cell signaling, and energy metabolism. Lysosomes act as the waste disposal system of the cell by digesting used materials in the cytoplasm, from both inside and outside the cell. Material from outside the cell is taken up through endocytosis, while material from the inside of the cell is digested through autophagy. The sizes of the organelles vary greatly—the larger ones can be more than 10 times the size of the smaller ones. They were discov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palmitoyl-CoA
Palmitoyl-CoA is an acyl-CoA thioester. It is an "activated" form of palmitic acid and can be transported into the mitochondrial matrix by the carnitine shuttle system (which transports fatty acyl-CoA molecules into the mitochondria), and once inside can participate in beta-oxidation. Alternatively, palmitoyl-CoA is used as a substrate in the biosynthesis of sphingosine (this biosynthetic pathway does not require transfer into the mitochondria). Biosynthesis Palmitoyl CoA formed from palmitic acid, in the reaction below. Palmitate + CoA-SH + ATP -> Palmitoyl-CoA + AMP + Pyrophosphate This reaction is often referred to as the "activation" of a fatty acid. The activation is catalyzed by palmitoyl-coenzyme A synthetase and the reaction proceeds through a two step mechanism, in which palmitoyl-AMP is an intermediate. The reaction is driven to completion by the exergonic hydrolysis of pyrophosphate. The activation of fatty acids occurs in the cytosol and beta-oxidation occurs i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palmitate
Palmitic acid (hexadecanoic acid in IUPAC nomenclature) is a fatty acid with a 16-carbon chain. It is the most common saturated fatty acid found in animals, plants and microorganisms.Gunstone, F. D., John L. Harwood, and Albert J. Dijkstra. The Lipid Handbook, 3rd ed. Boca Raton: CRC Press, 2007. , Its chemical formula is CH3(CH2)14COOH, and its C:D (the total number of carbon atoms to the number of carbon-carbon double-bonds) is 16:0. It is a major component of the oil from the fruit of oil palms (palm oil), making up to 44% of total fats. Meats, cheeses, butter, and other dairy products also contain palmitic acid, amounting to 50–60% of total fats. Palmitates are the salts and esters of palmitic acid. The palmitate anion is the observed form of palmitic acid at physiologic pH (7.4). Occurrence and production Palmitic acid was discovered by Edmond Frémy in 1840, in saponified palm oil. This remains the primary industrial route for its production, with the triglycerides (fat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cysteine
Cysteine (symbol Cys or C; ) is a semiessential proteinogenic amino acid with the formula . The thiol side chain in cysteine often participates in enzymatic reactions as a nucleophile. When present as a deprotonated catalytic residue, sometimes the symbol Cyz is used. The deprotonated form can generally be described by the symbol Cym as well. The thiol is susceptible to oxidation to give the disulfide derivative cystine, which serves an important structural role in many proteins. In this case, the symbol Cyx is sometimes used. When used as a food additive, it has the E number E920. Cysteine is encoded by the codons UGU and UGC. The sulfur-containing amino acids cysteine and methionine are more easily oxidized than the other amino acids. Structure Like other amino acids (not as a residue of a protein), cysteine exists as a zwitterion. Cysteine has chirality in the older / notation based on homology to - and -glyceraldehyde. In the newer ''R''/''S'' system of designating chi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
