Aspartic acid (symbol Asp or D ; the ionic form is known as aspartate ), is an α- amino acid that is used in the biosynthesis of proteins. The L -isomer of aspartic acid is one of the 22 proteinogenic amino acids , i.e., the building blocks of proteins . D -aspartic acid is one of two D -amino acids commonly found in mammals. Apart from a few rare exceptions, D -aspartic acid is not used for protein synthesis but is incorporated into some peptides and plays a role as a neurotransmitter / neuromodulator .
25-461: FECH may refer to: Ferrochelatase Student Federation of the University of Chile See also [ edit ] Fech Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title FECH . If an internal link led you here, you may wish to change the link to point directly to
50-653: A pK a of 3.9; however, in a peptide this is highly dependent on the local environment, and could be as high as 14. The one-letter code D for aspartate was assigned arbitrarily, with the proposed mnemonic aspar D ic acid. Aspartic acid was first discovered in 1827 by Auguste-Arthur Plisson and Étienne Ossian Henry by hydrolysis of asparagine , which had been isolated from asparagus juice in 1806. Their original method used lead hydroxide , but various other acids or bases are now more commonly used instead. There are two forms or enantiomers of aspartic acid. The name "aspartic acid" can refer to either enantiomer or
75-405: A carboxylic acid. Its α-amino group is in the protonated –NH 3 form under physiological conditions, while its α-carboxylic acid group is deprotonated −COO under physiological conditions. Aspartic acid has an acidic side chain (CH 2 COOH) which reacts with other amino acids, enzymes and proteins in the body. Under physiological conditions (pH 7.4) in proteins the side chain usually occurs as
100-411: A hydrogen acceptor in a chain of ATP synthase. Dietary L-aspartic acid has been shown to act as an inhibitor of Beta-glucuronidase , which serves to regulate enterohepatic circulation of bilirubin and bile acids. Click on genes, proteins and metabolites below to link to respective articles. Aspartate (the conjugate base of aspartic acid) stimulates NMDA receptors , though not as strongly as
125-499: A hydrophilic interior. The hydrophobic lips, consisting of the highly conserved residues 300–311, face the inner mitochondrial membrane and facilitate the passage of the poorly soluble protoporphyrin IX substrate and the heme product via the membrane. The interior of the active site pocket contains a highly conserved acidic surface that facilitates proton extraction from protoporphyrin. Histidine and aspartate residues roughly 20 angstroms from
150-531: A mitochondrial localization domain that is cleaved in post-translational modification . The folded domains contain a total of 17 α-helices and 8 β-sheets . The C terminal extension contains three of the four cysteine residues (Cys403, Cys406, Cys411) that coordinate the catalytic iron–sulfur cluster (2Fe-2S) . The fourth coordinating cysteine resides in the N-terminal domain (Cys196). The active pocket of ferrocheltase consists of two hydrophobic "lips" and
175-423: A mixture of two. Of these two forms, only one, " L -aspartic acid", is directly incorporated into proteins. The biological roles of its counterpart, " D -aspartic acid" are more limited. Where enzymatic synthesis will produce one or the other, most chemical syntheses will produce both forms, " DL -aspartic acid", known as a racemic mixture . In the human body, aspartate is most frequently synthesized through
200-400: Is biodegradable superabsorbent polymers (SAP), and hydrogels. Around 75% of superabsorbent polymers are used in disposable diapers and an additional 20% is used for adult incontinence and feminine hygiene products. Polyaspartic acid , the polymerization product of aspartic acid, is a biodegradable substitute to polyacrylate . In addition to SAP, aspartic acid has applications in
225-427: Is a metabolite in the urea cycle and participates in gluconeogenesis . It carries reducing equivalents in the malate-aspartate shuttle , which utilizes the ready interconversion of aspartate and oxaloacetate , which is the oxidized (dehydrogenated) derivative of malic acid . Aspartate donates one nitrogen atom in the biosynthesis of inosine , the precursor to the purine bases. In addition, aspartic acid acts as
250-494: Is an enzyme encoded by the FECH gene in humans. Ferrochelatase catalyses the eighth and terminal step in the biosynthesis of heme , converting protoporphyrin IX into heme B . It catalyses the reaction: Ferrochelatase catalyzes the insertion of ferrous iron into protoporphyrin IX in the heme biosynthesis pathway to form heme B. The enzyme is localized to the matrix-facing side of the inner mitochondrial membrane. Ferrochelatase
275-494: Is found in cytochrome b , a key component in Q-cytochrome c oxidoreductase (complex III) in oxidative phosphorylation . Human ferrochelatase is a homodimer composed of two 359 amino acid polypeptide chains. It has a total molecular weight of 85.07 kDa. Each subunit is composed of five regions: a mitochondrial localization sequence , the N terminal domain, two folded domains, and a C terminal extension. Residues 1–62 form
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#1732798242700300-462: Is the best known member of a family of enzymes that add divalent metal cations to tetrapyrrole structures. For example, magnesium chelatase adds magnesium to protoporphyrin IX in the first step of bacteriochlorophyll biosynthesis. Heme B is an essential cofactor in many proteins and enzymes. In particular, heme b plays a key role as the oxygen carrier in hemoglobin in red blood cells and myoglobin in muscle cells. Furthermore, heme B
325-483: Is the precursor to several amino acids, including four that are essential for humans: methionine , threonine , isoleucine , and lysine . The conversion of aspartate to these other amino acids begins with reduction of aspartate to its "semialdehyde", O 2 CCH(NH 2 )CH 2 CHO. Asparagine is derived from aspartate via transamidation: (where G C(O)NH 2 and G C(O)OH are glutamine and glutamic acid , respectively) Aspartate has many other biochemical roles. It
350-493: The fertilizer industry , where polyaspartate improves water retention and nitrogen uptake. Aspartic acid is not an essential amino acid , which means that it can be synthesized from central metabolic pathway intermediates in humans, and does not need to be present in the diet. In eukaryotic cells, roughly 1 in 20 amino acids incorporated into a protein is an aspartic acid, and accordingly almost any source of dietary protein will include aspartic acid. Additionally, aspartic acid
375-525: The transamination of oxaloacetate . The biosynthesis of aspartate is facilitated by an aminotransferase enzyme: the transfer of an amine group from another molecule such as alanine or glutamine yields aspartate and an alpha-keto acid. Industrially, aspartate is produced by amination of fumarate catalyzed by L- aspartate ammonia-lyase . Racemic aspartic acid can be synthesized from diethyl sodium phthalimidomalonate, (C 6 H 4 (CO) 2 NC(CO 2 Et) 2 ). In plants and microorganisms , aspartate
400-477: The Fe chaperone and complexes with ferrochelatase on its mitochondrial matrix side. Ferrochelatase can also insert other divalent metal ions into protoporphyrin. Some ions, such as Zn , Ni , and Co form other metalloporphyrins while heavier metal ions such as Mn , Pb , Hg , and Cd inhibit product release after metallation. Aspartate Like all other amino acids, aspartic acid contains an amino group and
425-478: The amino acid neurotransmitter L-glutamate does. In 2014, the global market for aspartic acid was 39.3 thousand short tons (35.7 thousand tonnes ) or about $ 117 million annually. The three largest market segments include the U.S., Western Europe, and China. Current applications include biodegradable polymers ( polyaspartic acid ), low calorie sweeteners ( aspartame ), scale and corrosion inhibitors, and resins. One area of aspartic acid market growth
450-404: The center of the active site on the mitochondrial matrix side of the enzyme coordinate metal binding. The mechanism of human protoporphyrin metalation remains under investigation. Many researchers have hypothesized distortion of the porphyrin macrocycle as key to catalysis. Researchers studying Bacillus subtilis ferrochelatase propose a mechanism for iron insertion into protoporphyrin in which
475-438: The enzyme tightly grips rings B, C, and D while bending ring A 36 . Normally planar, this distortion exposes the lone pair of electrons on the nitrogen in ring A to the Fe ion. Subsequent investigation revealed a 100 distortion in protoporphyrin bound to human ferrochelatase. A highly conserved histidine residue (His183 in B. subtilis , His263 in humans) is essential for determining the type of distortion, as well as acting as
500-421: The existence of an oligomeric complex that enables substrate channeling and coordination of overall iron and porphyrin metabolism throughout the cell. N-methylmesoporphyrin (N-MeMP) is a competitive inhibitor with protoporphyrin IX and is thought to be a transition state analog. As such, N-MeMP has been used extensively as a stabilizing ligand for x-ray crystallography structure determination. Frataxin acts as
525-546: The final metalation. Defects in ferrochelatase create a buildup of protoporphyrin IX, causing erythropoietic protoporphyria (EPP). The disease can result from a variety of mutations in FECH, most of which behave in an autosomal dominant manner with low clinical penetrance. Clinically, patients with EPP present with a range of symptoms, from asymptomatic to suffering from an extremely painful photosensitivity . In less than five percent of cases, accumulation of protoporphyrin in
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#1732798242700550-402: The initial proton acceptor from protoporphyrin. Anionic residues form a pathway facilitating proton movement away from the catalytic histidine. Frataxin chaperones iron to the matrix side of ferrochelatase, where aspartate and histidine residues on both proteins coordinate iron transfer into ferrochelatase. Two arginine and tyrosine residues in the active site (Arg164, Tyr165) may perform
575-484: The intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=FECH&oldid=932823140 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Ferrochelatase Protoporphyrin ferrochelatase (EC 4.98.1.1, formerly EC 4.99.1.1, or ferrochelatase ; systematic name protoheme ferro-lyase (protoporphyrin-forming) )
600-514: The liver results in cholestasis (blockage of bile flow from the liver to the small intestine) and terminal liver failure . In cases of lead poisoning , lead inhibits ferrochelatase activity, in part resulting in porphyria. Ferrochelatase interacts with numerous other enzymes involved in heme biosynthesis, catabolism , and transport, including protoporphyrinogen oxidase , 5-aminolevulinate synthase , ABCB10 , ABCB7 , succinyl-CoA synthetase , and mitoferrin-1. Multiple studies have suggested
625-483: The negatively charged aspartate form, −COO . It is a non- essential amino acid in humans, meaning the body can synthesize it as needed. It is encoded by the codons GAU and GAC. In proteins aspartate sidechains are often hydrogen bonded to form asx turns or asx motifs , which frequently occur at the N-termini of alpha helices . Aspartic acid, like glutamic acid , is classified as an acidic amino acid, with
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