Methylmalonyl-CoA Mutase
Methylmalonic Acid
Vitamin B 12
Acyl Coenzyme A
Propionates
Ornithine Decarboxylase
Isomerases
Malonates
Amino Acid Metabolism, Inborn Errors
Propionibacterium
Carboxy-Lyases
Glutamate Decarboxylase
Dopa Decarboxylase
Histidine Decarboxylase
Adenosylmethionine Decarboxylase
Uroporphyrinogen Decarboxylase
Orotidine-5'-Phosphate Decarboxylase
Tyrosine Decarboxylase
Polyamines
Eflornithine
Genetic heterogeneity in propionic acidemia patients with alpha-subunit defects. Identification of five novel mutations, one of them causing instability of the protein. (1/93)
The inherited metabolic disease propionic acidemia (PA) can result from mutations in either of the genes PCCA or PCCB, which encode the alpha and beta subunits, respectively, of the mitochondrial enzyme propionyl CoA-carboxylase. In this work we have analyzed the molecular basis of PCCA gene defects, studying mRNA levels and identifying putative disease causing mutations. A total of 10 different mutations, none predominant, are present in a sample of 24 mutant alleles studied. Five novel mutations are reported here for the first time. A neutral polymorphism and a variant allele present in the general population were also detected. To examine the effect of a point mutation (M348K) involving a highly conserved residue, we have carried out in vitro expression of normal and mutant PCCA cDNA and analyzed the mitochondrial import and stability of the resulting proteins. Both wild-type and mutant proteins were imported into mitochondria and processed into the mature form with similar efficiency, but the mature mutant M348K protein decayed more rapidly than did the wild-type, indicating a reduced stability, which is probably the disease-causing mechanism. (+info)Feasibility of DNA based methods for prenatal diagnosis and carrier detection of propionic acidaemia. (2/93)
Propionic acidaemia (PA) is an autosomal recessive disease caused by a genetic deficiency of propionyl-CoA carboxylase (PCC). Defects in the PCCA and PCCB genes that code for the alpha and beta subunits of PCC, respectively, are responsible for PA. A proband with PA was previously shown to carry the c1170insT mutation and the private L519P mutation in the PCCB gene. Here we report the prenatal diagnosis of an affected fetus based on DNA analysis in chorionic villus tissue. We have also assessed the carrier status in this PCCB deficient family, which was not possible with biochemical analysis. (+info)Genetic and biochemical characterization of the alpha and beta components of a propionyl-CoA carboxylase complex of Streptomyces coelicolor A3(2). (3/93)
Two genes, accA1 and accA2, with nearly identical nucleotide sequences were cloned from Streptomyces coelicolor A3(2). The deduced amino acid sequences of the product of these two genes showed high similarity to BcpA2 of Saccharopolyspora erythraea and other biotin-containing proteins from different organisms assumed to be the alpha subunit of a propionyl-CoA carboxylase. A gene, pccB, encoding the carboxyl transferase subunit of this enzyme complex was also characterized. Strains disrupted in accA1 did not show any change in acetyl- or propionyl-CoA carboxylase activity, whilst cell-free extracts of a pccB mutant strain contained a reduced level of propionyl-CoA carboxylase. No mutants in accA2 could be isolated, suggesting that the gene may be essential. Heterologous expression of accA1, accA2 and pccB in Escherichia col and in vitro reconstitution of enzyme activity confirmed that PccB is the beta subunit of a propionyl-CoA carboxylase and that either AccA1 or AccA2 could act as the alpha component of this enzyme complex. The fact that accA2 mutants appear to be inviable suggests that this gene encodes a biotinylated protein that might be shared with other carboxyl transferases essential for the growth of S. coelicolor. (+info)Potential relationship between genotype and clinical outcome in propionic acidaemia patients. (4/93)
Propionic acidaemia (PA) is an autosomal recessive disorder caused by mutations in either of the PCCA or PCCB genes which encode the alpha and beta subunits, respectively, of the mitochondrial enzyme propionyl-CoA carboxylase (PCC). In this work we have examined the biochemical findings and clinical outcome of 37 Spanish PA patients in relation to the mutations found in both PCCA and PCCB genes. We have detected 27 early-onset and 101 late-onset cases, showing remarkably similar biochemical features without relation to either the age of onset of the disease or the defective gene they have. Twenty-one of the patients have so far survived and three of them, now adolescents, present normal development. Different biochemical procedures allowed us to identify the defective gene in 9 PCCA deficient and 28 PCCB deficient patients. Nine putative disease-causing mutations accounting for 77.7% of mutant alleles were identified among PCCA deficient patients, each one carrying a unique genotypic combination. Of PCCB mutant alleles 98% were characterised. Four common mutations (ins/del, E168K, 1170insT and A497V) were found in 38/52 mutant chromosomes investigated, whereas the remainder of the alleles harbour 12 other different mutations. By examining the mutations identified both in PCCA and PCCB genes and the clinical evolution of patients, we have found a good correlation between certain mutations which can be considered as null with a severe phenotype, while certain missense mutations tend to be related to the late and mild forms of the disease. Expression studies, particularly of the missense mutations identified are necessary but other genetic and environmental factors probably contribute to the phenotypic variability observed in PA. (+info)High incidence of propionic acidemia in greenland is due to a prevalent mutation, 1540insCCC, in the gene for the beta-subunit of propionyl CoA carboxylase. (5/93)
Propionyl CoA carboxylase (PCC) is a mitochondrial, biotin-dependent enzyme involved in the catabolism of amino acids, odd-chain fatty acids, and other metabolites. PCC consists of two subunits, alpha and beta, encoded by the PCCA and PCCB genes, respectively. Inherited PCC deficiency due to mutations in either gene results in propionic acidemia (PA), an autosomal recessive disease. Surprisingly, PA is highly prevalent among Inuits in Greenland. We have analyzed reverse transcriptase-PCR products of the beta-subunit mRNA, to characterize the responsible mutation(s). A 3-bp insertion, 1540insCCC, was found in homozygous form in three patients and in compound heterozygous form in one patient. The resulting PCC has no measurable activity, and the mutant beta-subunit appears to be very unstable. To test the hypothesis that a common mutation is responsible for PA in the Greenlandic Inuit population, 310 anonymous DNA samples of Inuit origin were screened for 1540insCCC. We found a carrier frequency of 5%, which is very high compared with those of most other autosomal recessive diseases. Analysis of alleles of a very closely linked marker, D3S2453, revealed a high degree of linkage disequilibrium between one specific allele and 1540insCCC, suggesting that this mutation may be a founder mutation. (+info)Sodium ion-translocating decarboxylases. (6/93)
The review is concerned with three Na(+)-dependent biotin-containing decarboxylases, which catalyse the substitution of CO(2) by H(+) with retention of configuration (DeltaG degrees '=-30 kJ/mol): oxaloacetate decarboxylase from enterobacteria, methylmalonyl-CoA decarboxylase from Veillonella parvula and Propiogenium modestum, and glutaconyl-CoA decarboxylase from Acidaminococcus fermentans. The enzymes represent complexes of four functional domains or subunits, a carboxytransferase, a mobile alanine- and proline-rich biotin carrier, a 9-11 membrane-spanning helix-containing Na(+)-dependent carboxybiotin decarboxylase and a membrane anchor. In the first catalytic step the carboxyl group of the substrate is converted to a kinetically activated carboxylate in N-carboxybiotin. After swing-over to the decarboxylase, an electrochemical Na(+) gradient is generated; the free energy of the decarboxylation is used to translocate 1-2 Na(+) from the inside to the outside, whereas the proton comes from the outside. At high [Na(+)], however, the decarboxylases appear to catalyse a mere Na(+)/Na(+) exchange. This finding has implications for the life of P. modestum in sea water, which relies on the synthesis of ATP via Delta(mu)Na(+) generated by decarboxylation. In many sequenced genomes from Bacteria and Archaea homologues of the carboxybiotin decarboxylase from A. fermentans with up to 80% sequence identity have been detected. (+info)Biotin regulates the genetic expression of holocarboxylase synthetase and mitochondrial carboxylases in rats. (7/93)
Biotin is the cofactor of carboxylases [pyruvate (PC), propionyl-CoA (PCC), 3-methyl crotonyl-CoA and acetyl-CoA], to which it is covalently bound by the action of holocarboxylase synthetase (HCS). We have studied whether biotin also regulates their expression, as it does other, nonrelated enzymes (e.g., glucokinase, phosphoenol pyruvate carboxykinase, guanylate cyclase). For this purpose, HCS, PC and PCC mRNAs were studied in biotin-deficient rat liver, kidney, muscle and brain of biotin-deficient rats. PC- and PCC-specific activities and protein masses were also measured. The 24-h time course of HCS mRNA in deficient rats was examined after biotin supplementation. HCS mRNA was significantly reduced during vitamin deficiency. It increased in deficient rats after biotin was injected, reaching control levels 24 h after administration. These changes seem to be the first known instance in mammals of an effect of a water-soluble vitamin on a mRNA functionally related to it. In contrast, the decreased activities of the carboxylases were associated with reductions in the amounts of their enzyme proteins except in brain. However, their mRNA levels were not affected. There are no reports on these types of vitamin affecting the mRNA or protein levels of their apoenzymes or their products. This work provides evidence for biotin being a modulator of the genetic expression of the enzymes involved in its function as a cofactor. As such, it may be a useful model for probing a similar role for other water-soluble vitamins. (+info)Fatal propionic acidemia in mice lacking propionyl-CoA carboxylase and its rescue by postnatal, liver-specific supplementation via a transgene. (8/93)
Propionic acidemia (PA) is an inborn error of metabolism caused by the genetic deficiency of propionyl-CoA carboxylase (PCC). By disrupting the alpha-subunit gene of PCC, we created a mouse model of PA (PCCA(-/-)), which died in 24-36 h after birth due to accelerated ketoacidosis. A postnatal, liver-specific PCC expression via a transgene in a far lower level than that in wild-type liver, allowed PCCA(-/-) mice to survive the newborn and early infant periods, preventing a lethal fit of ketoacidosis (SAP(+)PCCA(-/-) mice). Interestingly, SAP(+)PCCA(-/-) mice, in which the transgene expression increased after the late infant period, continued to grow normally while mice harboring a persistent low level of PCC died in the late infant period due to severe ketoacidosis, clearly suggesting the requirement of increased PCC supplementation in proportion to the animal growth. Based on these results, we propose a two-step strategy to achieve an efficient PA prevention in human patients: a partial PCC supplementation in the liver during the newborn and early infant periods, followed by a larger amount of supplementation in the late infant period. (+info)Methylmalonyl-CoA mutase is a mitochondrial enzyme that plays a crucial role in the metabolism of certain amino acids and fatty acids. Specifically, it catalyzes the isomerization of methylmalonyl-CoA to succinyl-CoA, which is an important step in the catabolic pathways of valine, isoleucine, threonine, methionine, odd-chain fatty acids, and cholesterol.
The enzyme requires a cofactor called adenosylcobalamin (vitamin B12) for its activity. In the absence of this cofactor or due to mutations in the gene encoding the enzyme, methylmalonyl-CoA mutase deficiency can occur, leading to the accumulation of methylmalonic acid and other toxic metabolites, which can cause a range of symptoms including vomiting, dehydration, lethargy, hypotonia, developmental delay, and metabolic acidosis. This condition is typically inherited in an autosomal recessive manner and can be diagnosed through biochemical tests and genetic analysis.
Methylmalonic acid (MMA) is an organic compound that is produced in the human body during the metabolism of certain amino acids, including methionine and threonine. It is a type of fatty acid that is intermediate in the breakdown of these amino acids in the liver and other tissues.
Under normal circumstances, MMA is quickly converted to succinic acid, which is then used in the Krebs cycle to generate energy in the form of ATP. However, when there are deficiencies or mutations in enzymes involved in this metabolic pathway, such as methylmalonyl-CoA mutase, MMA can accumulate in the body and cause methylmalonic acidemia, a rare genetic disorder that affects approximately 1 in every 50,000 to 100,000 individuals worldwide.
Elevated levels of MMA in the blood or urine can be indicative of various metabolic disorders, including methylmalonic acidemia, vitamin B12 deficiency, and renal insufficiency. Therefore, measuring MMA levels is often used as a diagnostic tool to help identify and manage these conditions.
Vitamin B12, also known as cobalamin, is a water-soluble vitamin that plays a crucial role in the synthesis of DNA, formation of red blood cells, and maintenance of the nervous system. It is involved in the metabolism of every cell in the body, particularly affecting DNA regulation and neurological function.
Vitamin B12 is unique among vitamins because it contains a metal ion, cobalt, from which its name is derived. This vitamin can be synthesized only by certain types of bacteria and is not produced by plants or animals. The major sources of vitamin B12 in the human diet include animal-derived foods such as meat, fish, poultry, eggs, and dairy products, as well as fortified plant-based milk alternatives and breakfast cereals.
Deficiency in vitamin B12 can lead to various health issues, including megaloblastic anemia, fatigue, neurological symptoms such as numbness and tingling in the extremities, memory loss, and depression. Since vitamin B12 is not readily available from plant-based sources, vegetarians and vegans are at a higher risk of deficiency and may require supplementation or fortified foods to meet their daily requirements.
Acyl Coenzyme A (often abbreviated as Acetyl-CoA or Acyl-CoA) is a crucial molecule in metabolism, particularly in the breakdown and oxidation of fats and carbohydrates to produce energy. It is a thioester compound that consists of a fatty acid or an acetate group linked to coenzyme A through a sulfur atom.
Acyl CoA plays a central role in several metabolic pathways, including:
1. The citric acid cycle (Krebs cycle): In the mitochondria, Acyl-CoA is formed from the oxidation of fatty acids or the breakdown of certain amino acids. This Acyl-CoA then enters the citric acid cycle to produce high-energy electrons, which are used in the electron transport chain to generate ATP (adenosine triphosphate), the main energy currency of the cell.
2. Beta-oxidation: The breakdown of fatty acids occurs in the mitochondria through a process called beta-oxidation, where Acyl-CoA is sequentially broken down into smaller units, releasing acetyl-CoA, which then enters the citric acid cycle.
3. Ketogenesis: In times of low carbohydrate availability or during prolonged fasting, the liver can produce ketone bodies from acetyl-CoA to supply energy to other organs, such as the brain and heart.
4. Protein synthesis: Acyl-CoA is also involved in the modification of proteins by attaching fatty acid chains to them (a process called acetylation), which can influence protein function and stability.
In summary, Acyl Coenzyme A is a vital molecule in metabolism that connects various pathways related to energy production, fatty acid breakdown, and protein modification.
Propionates, in a medical context, most commonly refer to a group of medications that are used as topical creams or gels to treat fungal infections of the skin. Propionic acid and its salts, such as propionate, are the active ingredients in these medications. They work by inhibiting the growth of fungi, which causes the infection. Common examples of propionate-containing medications include creams used to treat athlete's foot, ringworm, and jock itch.
It is important to note that there are many different types of medications and compounds that contain the word "propionate" in their name, as it refers to a specific chemical structure. However, in a medical context, it most commonly refers to antifungal creams or gels.
Ornithine decarboxylase (ODC) is a medical/biochemical term that refers to an enzyme (EC 4.1.1.17) involved in the metabolism of amino acids, particularly ornithine. This enzyme catalyzes the decarboxylation of ornithine to form putrescine, which is a precursor for the synthesis of polyamines, such as spermidine and spermine. Polyamines play crucial roles in various cellular processes, including cell growth, differentiation, and gene expression.
Ornithine decarboxylase is a rate-limiting enzyme in polyamine biosynthesis, meaning that its activity regulates the overall production of these molecules. The regulation of ODC activity is tightly controlled at multiple levels, including transcription, translation, and post-translational modifications. Dysregulation of ODC activity has been implicated in several pathological conditions, such as cancer, neurodegenerative disorders, and inflammatory diseases.
Inhibitors of ornithine decarboxylase have been explored as potential therapeutic agents for various diseases, including cancer, due to their ability to suppress polyamine synthesis and cell proliferation. However, the use of ODC inhibitors in clinical settings has faced challenges related to toxicity and limited efficacy.
Isomerases are a class of enzymes that catalyze the interconversion of isomers of a single molecule. They do this by rearranging atoms within a molecule to form a new structural arrangement or isomer. Isomerases can act on various types of chemical bonds, including carbon-carbon and carbon-oxygen bonds.
There are several subclasses of isomerases, including:
1. Racemases and epimerases: These enzymes interconvert stereoisomers, which are molecules that have the same molecular formula but different spatial arrangements of their atoms in three-dimensional space.
2. Cis-trans isomerases: These enzymes interconvert cis and trans isomers, which differ in the arrangement of groups on opposite sides of a double bond.
3. Intramolecular oxidoreductases: These enzymes catalyze the transfer of electrons within a single molecule, resulting in the formation of different isomers.
4. Mutases: These enzymes catalyze the transfer of functional groups within a molecule, resulting in the formation of different isomers.
5. Tautomeres: These enzymes catalyze the interconversion of tautomers, which are isomeric forms of a molecule that differ in the location of a movable hydrogen atom and a double bond.
Isomerases play important roles in various biological processes, including metabolism, signaling, and regulation.
"Malonates" is not a recognized medical term. However, in chemistry, malonates refer to salts or esters of malonic acid, a dicarboxylic acid with the formula CH2(COOH)2. Malonic acid and its derivatives have been used in the synthesis of various pharmaceuticals and chemicals, but they are not typically associated with any specific medical condition or treatment. If you have encountered the term "malonates" in a medical context, it may be helpful to provide more information or seek clarification from the source.
Inborn errors of amino acid metabolism refer to genetic disorders that affect the body's ability to properly break down and process individual amino acids, which are the building blocks of proteins. These disorders can result in an accumulation of toxic levels of certain amino acids or their byproducts in the body, leading to a variety of symptoms and health complications.
There are many different types of inborn errors of amino acid metabolism, each affecting a specific amino acid or group of amino acids. Some examples include:
* Phenylketonuria (PKU): This disorder affects the breakdown of the amino acid phenylalanine, leading to its accumulation in the body and causing brain damage if left untreated.
* Maple syrup urine disease: This disorder affects the breakdown of the branched-chain amino acids leucine, isoleucine, and valine, leading to their accumulation in the body and causing neurological problems.
* Homocystinuria: This disorder affects the breakdown of the amino acid methionine, leading to its accumulation in the body and causing a range of symptoms including developmental delay, intellectual disability, and cardiovascular problems.
Treatment for inborn errors of amino acid metabolism typically involves dietary restrictions or supplementation to manage the levels of affected amino acids in the body. In some cases, medication or other therapies may also be necessary. Early diagnosis and treatment can help prevent or minimize the severity of symptoms and health complications associated with these disorders.
Propionibacterium is a genus of gram-positive, rod-shaped bacteria that are commonly found on the skin and in the mouth, intestines, and genitourinary tract of humans and animals. They are named after their ability to produce propionic acid as a major metabolic end product. Some species of Propionibacterium, such as P. acnes, are associated with skin conditions like acne vulgaris, where they contribute to the inflammatory response that leads to the formation of pimples and lesions. Other species, such as P. freudenreichii, are used in the food industry for the production of dairy products like Swiss cheese and yogurt. Propionibacterium species are generally considered to be non-pathogenic or opportunistic pathogens, meaning that they can cause infection under certain circumstances, such as when the immune system is compromised.
Carboxy-lyases are a class of enzymes that catalyze the removal of a carboxyl group from a substrate, often releasing carbon dioxide in the process. These enzymes play important roles in various metabolic pathways, such as the biosynthesis and degradation of amino acids, sugars, and other organic compounds.
Carboxy-lyases are classified under EC number 4.2 in the Enzyme Commission (EC) system. They can be further divided into several subclasses based on their specific mechanisms and substrates. For example, some carboxy-lyases require a cofactor such as biotin or thiamine pyrophosphate to facilitate the decarboxylation reaction, while others do not.
Examples of carboxy-lyases include:
1. Pyruvate decarboxylase: This enzyme catalyzes the conversion of pyruvate to acetaldehyde and carbon dioxide during fermentation in yeast and other organisms.
2. Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO): This enzyme is essential for photosynthesis in plants and some bacteria, as it catalyzes the fixation of carbon dioxide into an organic molecule during the Calvin cycle.
3. Phosphoenolpyruvate carboxylase: Found in plants, algae, and some bacteria, this enzyme plays a role in anaplerotic reactions that replenish intermediates in the citric acid cycle. It catalyzes the conversion of phosphoenolpyruvate to oxaloacetate and inorganic phosphate.
4. Aspartate transcarbamylase: This enzyme is involved in the biosynthesis of pyrimidines, a class of nucleotides. It catalyzes the transfer of a carboxyl group from carbamoyl aspartate to carbamoyl phosphate, forming cytidine triphosphate (CTP) and fumarate.
5. Urocanase: Found in animals, this enzyme is involved in histidine catabolism. It catalyzes the conversion of urocanate to formiminoglutamate and ammonia.
Glutamate decarboxylase (GAD) is an enzyme that plays a crucial role in the synthesis of the neurotransmitter gamma-aminobutyric acid (GABA) in the brain. GABA is an inhibitory neurotransmitter that helps to balance the excitatory effects of glutamate, another neurotransmitter.
Glutamate decarboxylase catalyzes the conversion of glutamate to GABA by removing a carboxyl group from the glutamate molecule. This reaction occurs in two steps, with the enzyme first converting glutamate to glutamic acid semialdehyde and then converting that intermediate product to GABA.
There are two major isoforms of glutamate decarboxylase, GAD65 and GAD67, which differ in their molecular weight, subcellular localization, and function. GAD65 is primarily responsible for the synthesis of GABA in neuronal synapses, while GAD67 is responsible for the synthesis of GABA in the cell body and dendrites of neurons.
Glutamate decarboxylase is an important target for research in neurology and psychiatry because dysregulation of GABAergic neurotransmission has been implicated in a variety of neurological and psychiatric disorders, including epilepsy, anxiety, depression, and schizophrenia.
Dopa decarboxylase (DDC) is an enzyme that plays a crucial role in the synthesis of dopamine and serotonin, two important neurotransmitters in the human body. This enzyme is responsible for converting levodopa (L-DOPA), an amino acid precursor, into dopamine, a critical neurotransmitter involved in movement regulation, motivation, reward, and mood.
The gene that encodes dopa decarboxylase is DDC, located on chromosome 7p12.2-p12.1. The enzyme is widely expressed throughout the body, including the brain, kidneys, liver, and gut. In addition to its role in neurotransmitter synthesis, dopa decarboxylase also contributes to the metabolism of certain drugs, such as levodopa and carbidopa, which are used in the treatment of Parkinson's disease.
Deficiencies or mutations in the DDC gene can lead to various neurological disorders, including aromatic L-amino acid decarboxylase deficiency (AADCD), a rare autosomal recessive disorder characterized by decreased levels of dopamine and serotonin. Symptoms of AADCD may include developmental delay, movement disorders, seizures, autonomic dysfunction, and oculogyric crises.
Histidine Decarboxylase is a medical term that refers to an enzyme found in various organisms, including humans. This enzyme plays a crucial role in the conversion of the amino acid L-histidine into histamine, which is a biogenic amine that acts as a neurotransmitter and inflammatory mediator in the human body.
Histidine decarboxylase is found in several tissues, including the central nervous system, gastrointestinal tract, and skin. It requires pyridoxal 5'-phosphate (PLP) as a cofactor for its enzymatic activity. Abnormal levels or activity of histidine decarboxylase have been implicated in several medical conditions, including allergic reactions, inflammation, and neuropsychiatric disorders.
Inhibitors of histidine decarboxylase are being investigated as potential therapeutic agents for the treatment of various diseases, such as mast cell-mediated disorders, gastrointestinal disorders, and neurological conditions associated with abnormal histamine levels.
Adenosylmethionine decarboxylase (AdoMetDC) is an enzyme that plays a crucial role in the biosynthesis of polyamines, which are essential molecules for cell growth and differentiation. The enzyme catalyzes the decarboxylation of S-adenosylmethionine (SAM) to produce decarboxylated SAM, also known as deoxyadenosylcobalamin or coenzyme M.
Decarboxylated SAM serves as an aminopropyl group donor in the biosynthesis of polyamines such as spermidine and spermine. These polyamines are involved in various cellular processes, including DNA replication, transcription, translation, protein synthesis, and cell signaling.
AdoMetDC is a pyridoxal-5'-phosphate (PLP)-dependent enzyme that requires the cofactor vitamin B12 for its activity. It is found in various organisms, including bacteria, yeast, plants, and animals. In humans, AdoMetDC is encoded by the AMD1 gene and is localized mainly in the cytosol of cells.
Dysregulation of AdoMetDC activity has been implicated in several diseases, such as cancer, neurodegenerative disorders, and cardiovascular diseases. Therefore, targeting AdoMetDC with inhibitors or activators has emerged as a potential therapeutic strategy for treating these conditions.
Uroporphyrinogen decarboxylase is a vital enzyme in the biosynthetic pathway of heme, which is a crucial component of hemoglobin in red blood cells. This enzyme is responsible for catalyzing the decarboxylation of uroporphyrinogen III, a colorless porphyrinogen, to produce coproporphyrinogen III, a brownish-red porphyrinogen.
The reaction involves the sequential removal of four carboxyl groups from the four acetic acid side chains of uroporphyrinogen III, resulting in the formation of coproporphyrinogen III. This enzyme's activity is critical for the normal biosynthesis of heme, and any defects or deficiencies in its function can lead to various porphyrias, a group of metabolic disorders characterized by the accumulation of porphyrins and their precursors in the body.
The gene responsible for encoding uroporphyrinogen decarboxylase is UROD, located on chromosome 1p34.1. Mutations in this gene can lead to a deficiency in the enzyme's activity, causing an autosomal recessive disorder known as congenital erythropoietic porphyria (CEP), also referred to as Günther's disease. This condition is characterized by severe photosensitivity, hemolytic anemia, and scarring or thickening of the skin.
Orotidine-5’-phosphate decarboxylase (ODC) is an enzyme that is involved in the synthesis of pyrimidines, which are essential nucleotides required for the production of DNA and RNA. The gene that encodes this enzyme is called UMPS.
ODC catalyzes the decarboxylation of orotidine-5’-phosphate (OMP) to form uridine monophosphate (UMP), which is a precursor to other pyrimidines such as cytidine triphosphate (CTP) and thymidine triphosphate (TTP). This reaction is the fifth step in the de novo synthesis of pyrimidines.
Defects in the ODC enzyme can lead to a rare genetic disorder called orotic aciduria, which is characterized by an accumulation of orotic acid and orotidine in the urine, as well as neurological symptoms such as developmental delay, seizures, and ataxia. Treatment for this condition typically involves supplementation with uridine and a low-protein diet to reduce the production of excess orotic acid.
Tyrosine decarboxylase is an enzyme that catalyzes the decarboxylation of the amino acid tyrosine to form the biogenic amine tyramine. The reaction occurs in the absence of molecular oxygen and requires pyridoxal phosphate as a cofactor. Tyrosine decarboxylase is found in various bacteria, fungi, and plants, and it plays a role in the biosynthesis of alkaloids and other natural products. In humans, tyrosine decarboxylase is not normally present, but its activity has been detected in some tumors and is associated with the production of neurotransmitters in neuronal cells.
Polyamines are organic compounds with more than one amino group (-NH2) and at least one carbon atom bonded to two or more amino groups. They are found in various tissues and fluids of living organisms and play important roles in many biological processes, such as cell growth, differentiation, and apoptosis (programmed cell death). Polyamines are also involved in the regulation of ion channels and transporters, DNA replication and gene expression. The most common polyamines found in mammalian cells are putrescine, spermidine, and spermine. They are derived from the decarboxylation of amino acids such as ornithine and methionine. Abnormal levels of polyamines have been associated with various pathological conditions, including cancer and neurodegenerative diseases.
Eflornithine is a antiprotozoal medication, which is used to treat sleeping sickness (human African trypanosomiasis) caused by Trypanosoma brucei gambiense in adults and children. It works by inhibiting the enzyme ornithine decarboxylase, which is needed for the growth of the parasite. By doing so, it helps to control the infection and prevent further complications.
Eflornithine is also used as a topical cream to slow down excessive hair growth in women due to a condition called hirsutism. It works by interfering with the growth of hair follicles.
It's important to note that Eflornithine should be used under the supervision of a healthcare professional, and it may have side effects or interactions with other medications.
Putrescine is an organic compound with the chemical formula NH2(CH2)4NH2. It is a colorless, viscous liquid that is produced by the breakdown of amino acids in living organisms and is often associated with putrefaction, hence its name. Putrescine is a type of polyamine, which is a class of organic compounds that contain multiple amino groups.
Putrescine is produced in the body through the decarboxylation of the amino acid ornithine by the enzyme ornithine decarboxylase. It is involved in various cellular processes, including the regulation of gene expression and cell growth. However, at high concentrations, putrescine can be toxic to cells and has been implicated in the development of certain diseases, such as cancer.
Putrescine is also found in various foods, including meats, fish, and some fruits and vegetables. It contributes to the unpleasant odor that develops during spoilage, which is why putrescine is often used as an indicator of food quality and safety.