Names | |
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IUPAC name (2R)-2-Amino-3-[[(2R)-2-amino-3-hydroxy-3-oxopropyl] sulfanylmethylsulfanyl]propanoic acid | |
Other names Djenkolate; Jengkolic acid; S,S'-Methylenebiscysteine [1] | |
Identifiers | |
3D model (JSmol) | |
ChEBI | |
ChemSpider | |
ECHA InfoCard | 100.007.150 |
EC Number |
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KEGG | |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C7H14N2O4S2 | |
Molar mass | 254.33 g/mol |
1.02 g L−1 (at 30±0.5°C) [2] | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Djenkolic acid (or sometimes jengkolic acid) is a sulfur-containing non-protein amino acid naturally found in the djenkol beans of the Southeast Asian plant Archidendron jiringa . Its chemical structure is similar to cystine but contains a methylene (single carbon) unit in between the two sulfur atoms. There is about 20 grams of djenkolic acid per kilogram of dry djenkol beans, and it has also been reported in smaller amounts in the seeds of other leguminous plants such as Leucaena esculenta (2.2 g/kg) and Pithecolobium ondulatum (2.8 g/kg). [3]
The toxicity of djenkolic acid in humans arises from its poor solubility under acidic conditions after consumption of the djenkol bean. [3] The amino acid precipitates into crystals which cause mechanical irritation of the renal tubules and urinary tract, resulting in symptoms such as abdominal discomfort, loin pains, severe colic, nausea, vomiting, dysuria, gross hematuria, and oliguria, occurring 2 to 6 hours after the beans were ingested. [4] Urine analysis of patients reveals erythrocytes, epithelial cells, protein, and the needle-like crystals of djenkolic acid. Urolithiasis can also happen, with djenkolic acid as the nucleus. In young children, it has also been reported to produce painful swelling of the genitalia. [5]
Treatment for this toxicity requires hydration to increase urine flow and alkalinization of urine by sodium bicarbonate. Furthermore, this poisoning can be prevented when consuming djenkol beans by boiling them beforehand, since djenkolic acid is removed from the beans. [4]
Djenkolic acid was first isolated by Van Veen and Hyman in 1933 [6] from the urine of the natives of Java who had eaten the djenkol bean and were suffering from poisoning. They then isolated the djenkolic acid crystals by treating the djenkol beans with barium hydroxide at 30°C for a prolonged period. [2]
Du Vigneaud and Patterson managed to synthesize djenkolic acid by condensation of methylene chloride with 2 moles of L-cysteine in liquid ammonia. [2] Later on, Armstrong and du Vigneaud prepared djenkolic acid by the direct combination of 1 mole of formaldehyde with 2 moles of L-cysteine in a strongly acidic solution. [7]
Cysteine is a semiessential proteinogenic amino acid with the formula HOOC−CH(−NH2)−CH2−SH. The thiol side chain in cysteine often participates in enzymatic reactions as a nucleophile. Cysteine is chiral, with only L-cysteine being found in nature.
An essential amino acid, or indispensable amino acid, is an amino acid that cannot be synthesized from scratch by the organism fast enough to supply its demand, and must therefore come from the diet. Of the 21 amino acids common to all life forms, the nine amino acids humans cannot synthesize are valine, isoleucine, leucine, methionine, phenylalanine, tryptophan, threonine, histidine, and lysine.
α2-Macroglobulin (α2M) or alpha-2-macroglobulin is a large plasma protein found in the blood. It is mainly produced by the liver, and also locally synthesized by macrophages, fibroblasts, and adrenocortical cells. In humans it is encoded by the A2M gene.
Cystinuria is an inherited autosomal recessive disease characterized by high concentrations of the amino acid cystine in the urine, leading to the formation of cystine stones in the kidneys, ureters, and bladder. It is a type of aminoaciduria. "Cystine", not "cysteine," is implicated in this disease; the former is a dimer of the latter.
Rieske proteins are iron–sulfur protein (ISP) components of cytochrome bc1 complexes and cytochrome b6f complexes and are responsible for electron transfer in some biological systems. John S. Rieske and co-workers first discovered the protein and in 1964 isolated an acetylated form of the bovine mitochondrial protein. In 1979 Trumpower's lab isolated the "oxidation factor" from bovine mitochondria and showed it was a reconstitutively-active form of the Rieske iron-sulfur protein
It is a unique [2Fe-2S] cluster in that one of the two Fe atoms is coordinated by two histidine residues rather than two cysteine residues. They have since been found in plants, animals, and bacteria with widely ranging electron reduction potentials from -150 to +400 mV.
Cyanogen bromide is the inorganic compound with the formula (CN)Br or BrCN. It is a colorless solid that is widely used to modify biopolymers, fragment proteins and peptides, and synthesize other compounds. The compound is classified as a pseudohalogen.
The branched-chain α-ketoacid dehydrogenase complex is a multi-subunit complex of enzymes that is found on the mitochondrial inner membrane. This enzyme complex catalyzes the oxidative decarboxylation of branched, short-chain alpha-ketoacids. BCKDC is a member of the mitochondrial α-ketoacid dehydrogenase complex family comprising pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase, key enzymes that function in the Krebs cycle.
Cysteine proteases, also known as thiol proteases, are hydrolase enzymes that degrade proteins. These proteases share a common catalytic mechanism that involves a nucleophilic cysteine thiol in a catalytic triad or dyad.
Cysteine metabolism refers to the biological pathways that consume or create cysteine. The pathways of different amino acids and other metabolites interweave and overlap to creating complex systems.
In enzymology, sarcosine dehydrogenase (EC 1.5.8.3) is a mitochondrial enzyme that catalyzes the chemical reaction N-demethylation of sarcosine to give glycine. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-NH group of donor with other acceptors. The systematic name of this enzyme class is sarcosine:acceptor oxidoreductase (demethylating). Other names in common use include sarcosine N-demethylase, monomethylglycine dehydrogenase, and sarcosine:(acceptor) oxidoreductase (demethylating). Sarcosine dehydrogenase is closely related to dimethylglycine dehydrogenase, which catalyzes the demethylation reaction of dimethylglycine to sarcosine. Both sarcosine dehydrogenase and dimethylglycine dehydrogenase use FAD as a cofactor. Sarcosine dehydrogenase is linked by electron-transferring flavoprotein (ETF) to the respiratory redox chain. The general chemical reaction catalyzed by sarcosine dehydrogenase is:
In enzymology, histidinol dehydrogenase (HIS4) (HDH) (EC 1.1.1.23) is an enzyme that catalyzes the chemical reaction
In enzymology, a 3-mercaptopyruvate sulfurtransferase is an enzyme that catalyzes the chemical reactions of 3-mercaptopyruvate. This enzyme belongs to the family of transferases, specifically the sulfurtransferases. This enzyme participates in cysteine metabolism. It is encoded by the MPST gene.
In enzymology, a tRNA sulfurtransferase is an enzyme that catalyzes the chemical reaction
Glutamate–cysteine ligase (GCL) EC 6.3.2.2), previously known as γ-glutamylcysteine synthetase (GCS), is the first enzyme of the cellular glutathione (GSH) biosynthetic pathway that catalyzes the chemical reaction:
Felinine, also known as (R)-2-amino-3-(4-hydroxy-2-methylbutan-2-ylthio)propanoic acid, is an amino acid found in cat urine and a precursor via microbial lyase of the putative cat pheromone and thiol called 3-mercapto-3-methylbutan-1-ol (MMB). Felinine is excreted by some Felidae species, including bobcats, Chinese desert cats, the kodkod, and domestic cats.
In enzymology, a serine O-acetyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a cystathionine gamma-synthase is an enzyme that catalyzes the formation of cystathionine from cysteine and an activated derivative of homoserine, e.g.:
Lipoamide acyltransferase component of branched-chain alpha-keto acid dehydrogenase complex, mitochondrial is an enzyme that in humans is encoded by the DBT gene.
Archidendron pauciflorum, commonly known as djenkol, jengkol or jering is a species of flowering tree in the pea family, Fabaceae. It is native to Southeast Asia, where the seeds are a popular dish. They are mainly consumed in Indonesia, Thailand, Myanmar, and Vietnam, prepared by frying, boiling, or roasting, and eaten raw. The beans are mildly toxic due to the presence of djenkolic acid, an amino acid that causes djenkolism. The beans and leaves of the djenkol tree are traditionally used for medicinal purposes such as purifying the blood. To date, djenkol is traded on local markets only.
In molecular biology, the amylin protein family or calcitonin/CGRP/IAPP protein family is a family of proteins, which includes the precursors of calcitonin/calcitonin gene-related peptide (CGRP), islet amyloid polypeptide (IAPP) and adrenomedullin.