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Diphosphomevalonate decarboxylase (MVD) catalyzes the conversion of mevalonate pyrophosphate into isopentenyl pyrophosphate in one of the early steps in cholesterol biosynthesis. MVD decarboxylates and dehydrates its substrate while hydrolyzing ATP. MVD is expressed in the heart, skeletal muscle, lung, liver, brain, pancreas, kidney and placenta.

Uridine 5'-monophosphate synthase (UMPS), is a bifunctional enzyme that catalyzes the ultimate two steps of the de novo pyrimidine biosynthetic pathway. UMPS in eukaryotes links the orotate phosphoribosyltransferase and the orotidine-5’-monophosphate (OMP) decarboxylase activities into a single protein. The harmony of these 2 enzymes is assumed to be stabilized the catalytic centers as a result of the low molar concentration of the protein in mammalian cells. Mutations in UMPS are the reason of inherited orotic aciduria disease.

IFIH1 is a DEAD box protein which is upregulated in response to treatment with beta-interferon and a protein kinase C-activating compound, mezerein. Irreversible reprogramming of melanomas can be attained by therapy with both these agents; treatment with either agent alone only achieves reversible differentiation. DEAD box proteins are implicated in several cellular processes involving alteration of RNA secondary structure such as translation initiation, nuclear and mitochondrial splicing, and ribosome and spliceosome assembly.

Creatine Kinase, Mitochondrial 2 (CKMT2) is a member of the ATP:guanido phosphotransferase family. CKMT2 is responsible for the transfer of high energy phosphate from mitochondria to the cytosolic carrier, creatine. CKMT2 reversibly catalyzes the transfer of phosphate between ATP and various phosphogens (e.g. creatine phosphate). Creatine kinase isoenzymes have a principal role in energy transduction in tissues with large, variable energy demands, such as skeletal muscle, heart, brain and spermatozoa. Mitochondrial creatine kinase occurs in 2 different oligomeric forms: dimers and octamers, contrary to the exclusively dimeric cytosolic creatine kinase isoenzymes. The CKMT2 gene contains sequences homologous to a number of motifs which are shared among some nuclear genes encoding mitochondrial proteins and therefore may be crucial for the coordinated activation of these genes during mitochondrial biogenesis.

Myristate, a rare 14-carbon saturated fatty acid, is co-translationally attached by an amide linkage to the N-terminal glycine residue of cellular & viral proteins with various functions. N-Myristoyltransferase 1, also known as NMT1 catalyzes the transfer of myristate from CoA to proteins. NMT1 seems to be irreversible and is essential for full expression of the biologic activities of several N-myristoylated proteins, as well as the alpha subunit of the signal-transducing guanine nucleotide-binding protein, G protein.

Phospholipase A2 (PLA2) catalyzes the hydrolysis of the sn-2 position of membrane glycerophospholipids to liberate arachidonic acid (AA), a precursor of eicosanoids including prostaglandins and leukotrienes. The same reaction also produces lysophosholipids, which represent another class of lipid mediators.
The secretory PLA2 (sPLA2) family, in which 10 isozymes have been identified, consists of lowmolecular weight, Ca2+-requiring secretory enzymes that have been implicated in a number of biological processes, such as modification of eicosanoid generation, inflammation, and host defense.
This enzyme has been proposed to hydrolyze phosphatidylcholine (PC) in lipoproteins to liberate lyso- PC and free fatty acids in the arterial wall, thereby facilitating the accumulation of bioactive lipids and modified lipoproteins in atherosclerotic foci.
In mice, sPLA2 expression significantly influences HDL particle size and composition and demonstrate that an induction of sPLA2 is required for the decrease in plasma HDL cholesterol in response to inflammatory stimuli. Instillation of bacteria into the bronchi was associated with surfactant degradation and a decrease in large:small ratio of surfactant aggregates in rats.
sPLA2-IIA can exert beneficial action in the context of infectious diseases since recent studies have shown that this enzyme exhibits potent bactericidal effects. Induction of the synthesis of sPLA2-IIA is generally initiated by endotoxin and a limited number of cytokines via paracrine and/or autocrine processes.

GGH is a homodimeric protein which catalyzes the cleavage of the gamma-glutamyl chain of folylpoly-gamma-glutamyl substrates. GGH is a vital enzyme in folyl and antifolyl poly-gamma-glutamate metabolism and it has a significant part in the bioavailability of dietary pteroylpolyglutamates and in the metabolism of antifolates and pteroylpolyglutamates.

Lipid hydroperoxide peroxidase (TPX) belongs to the peroxiredoxin family of antioxidant enzymes, which reduce hydrogen peroxide and alkyl hydroperoxides. TPX has an imperative role in thioredoxin peroxidase activity.

Acyl-protein thioesterase 2 (LYPLA2) is lysophospholipase which acts on biological membranes to regulate the multifunctional lysophospholipids. LYPLA2 may hydrolyze fatty acids from S-acylated cysteine residues in proteins such as trimeric G alpha proteins or HRAS.

Serine racemase (SRR) is an enzyme which generates D-serine from L-serine. D-serine functions as a neuronal signaling molecule by activating NMDA receptors in the brain. Mammalian SRR is a pyridoxal 5'-phosphate dependent enzyme which catalyzes both the racemization of L-serine to D-serine and also the elimination of water from L-serine, producing pyruvate and ammonia. The SRR enzyme is physiologically stimulated by divalent cations (e.g., magnesium) and is allosterically activated by the magnesium/ATP complex.

Peptidase Inhibitor 16 (PI16) which a member of the CRISP family, is a putative serine protease inhibitor. PI16 interacts with PSP94/MSMB. PI16 is expressed in the prostate, testis, ovary and intestine. It also concentrates in prostate cancer patient's sera. PI16 may serve as a marker following prostatectomy for prostate cancer.

Methionine sulfoxide reductase A (MSRA) is a member of the MsrA Met sulfoxide reductase family. The MSRA enzyme has a vital function as a repair enzyme for proteins which have been inactivated by oxidation. MSRA catalyzes the reversible oxidation-reduction of methionine sulfoxide in proteins to methionine. The three substrates of the MSRA enzyme are peptide-L-methionine, thioredoxin disulfide, and H2O, while its 2 products are peptide-L-methionine (R)-S-oxide and thioredoxin. The MSRA protein is ubiquitous and extremely conserved. Human and animal studies have shown the ultimate levels of expression in kidney and nervous tissue.

Inositol oxygenase is a non-heme di-iron enzyme which oxidizes myo-inositol to glucuronic acid. In addition, inositol oxygenase oxidizes the less abundant chiro isomer of inositol. MIOX enzyme is a component of the only known pathway for the catabolism of inositol in humans. MIOX is expressed mostly in the kidneys. Reduction of Inositol Oxygenase and accumulation of polyols, such as inositol and xylitol, have been implicated as contributing factors in complications linked with diabetes.

Hexokinases phosphorylate glucose to produce glucose-6-phosphate, thus committing glucose to the glycolytic pathway. Alternative splicing of Glucokinase results in three tissue-specific forms of glucokinase, one found in pancreatic islet beta cells and two found in liver. The protein localizes to the outer membrane of mitochondria. In contrast to other forms of hexokinase, HK4 is not inhibited by its product glucose-6-phosphate but remains active while glucose is abundant. Mutations in this gene have been associated with non-insulin dependent diabetes mellitus (NIDDM), maturity onset diabetes of the young, type 2 (MODY2) and persistent hyperinsulinemic hypoglycemia of infancy (PHHI).

COMT catalyzes the transfer of a methyl group from S-adenosylmethionine (SAM) to catechol substrates such as the neurotransmitters. This O-methylation results in one of the main degradative pathways of the catecholamine transmitters. COMT COMT is located in the postsynaptic neuron and is involved in the metabolism of catechol estrogen drugs used in the treatment of hypertension, asthma, Parkinson disease and the inactivation of catecholamine neurotransmitters though enzymatic degradation. COMT appears in tissues in 2 forms, a soluble form and a membrane-bound form which differ in their N-termini. COMT inhibitors increase its availability and are used in the treatment of patients with Parkinson's disease.

RNMT is a widely expressed nuclear protein which is a member of the mRNA cap methyltransferase family. Cap-dependent mRNA translation requires the methylation of the mRNA guanosine cap by RNMT. RNMT catalyzes the transfer of a methyl group from AdoMet (S-adenosylmethionine) to the GpppN end of the growing mRNA at the N-7 position, thus producing AdoHyc (S-adenosylhomocysteine) and m7GpppN terminated RNA.

Paraoxonase 2 (PON2) is a member of a multigene family whose genes share 65% identity at the amino acid level, and is expressed in a variety of tissues, including the pancreas. PON2 overexpression has been shown to lower the intracellular oxidative state and reduce the cells ability to oxidize LDL. PON2 is therefore implicated in the modulation of oxidative stress.

Phospholysine phosphohistidine inorganic pyrophosphate phosphatase (LHPP) belongs to the HAD-like hydrolase superfamily. LHPP is an exceptional enzyme which hydrolyzes not only oxygen-phosphorus bonds in inorganic pyrophosphate but also nitrogen-phosphorus bonds in phospholysine, phosphohistidine and imidodiphosphate in vitro. LHPP is expressed in the liver, kidney and moderately in the brain.

ADP-ribosylhydrolase like 2 (ADPRHL2) belongs to the ADP-ribosylglycohydrolase family. ADPRHL2 catalyzes the removal of ADP-ribose from ADP-ribosylated proteins. ADPRHL2, which is ubiquitously expressed, uses magnesium as a cofactor to catalyze the hydrolysis of poly (ADP-ribose) that is synthesized after DNA damage. Furthermore, ADPRHL2 has an essential role in the maintenance of normal neuronal cell function. The ADPRHL2 enzyme localizes to the mitochondria, in addition to the nucleus and cytoplasm.

NADH Dehydrogenase Flavoprotein 2 (NDUFV2) is a 24 kDa Core subunit of the mitochondrial membrane respiratory chain NADH dehydrogenase (Complex I) which is a part of the minimal assembly required for catalysisthe. NDUFV2 is aslo involved in electron transfer. Mutations in NDUFV2 are implicated in Parkinson's disease, bipolar disorder, schizophrenia, and have been discovered in one case of early onset hypertrophic cardiomyopathy and encephalopathy.

Creatine Kinase MM is a cytoplasmic enzyme involved in energy homeostasis and is an important serum marker for myocardial infarction. The encoded protein reversibly catalyzes the transfer of phosphate between ATP and various phosphogens such as creatine phosphate. It acts as a homodimer in striated muscle as well as in other tissues, and as a heterodimer with a similar brain isozyme in heart. The encoded protein is a member of the ATP:guanido phosphotransferase protein family.

Alcohol dehydrogenase 1A (ADH1A) is a member of the alcohol dehydrogenase family. ADH1A has a key role in ethanol metabolism. ADH1A along with coenzyme NAD catalyzes the reversible conversion of organic alcohols to ketones or aldehydes. The physiologic function of ADH1A in the liver is the elimination of ethanol formed by microorganisms in the intestinal tract. ADH1A is monomorphic and predominant in fetal and infant livers, growing to be less active in gestation and only weakly active during adulthood.

TALDO1 is a important enzyme of the non-oxidative pentose phosphate pathway supplying ribose-5-phosphate for nucleic acid synthesis and NADPH for lipid biosynthesis. TALDO1 delivers a dihydroxyacetone group from donor compounds (fructose 6-phosphate or sedoheptulose 7-phosphate) to aldehyde acceptor compounds. TALDO1 is expressed at selectively great levels in oligodendrocytes of the brain. TALDO1 Deficiency results in accumulation of erythritol, D-arabitol, and ribitol.