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Glycerol dehydrogenase (GldA) catalyzes the NAD-dependent oxidation of glycerol to dihydroxyacetone (glycerone). The GldA protein allows microorganisms to use glycerol as a source of carbon under anaerobic conditions. Furthermore, in E.coli GldA has an imperative role by regulating the intracellular level of dihydroxyacetone by catalyzing the reverse reaction, i.e. the conversion of dihydroxyacetone into glycerol. GldA possesses an extensive substrate specificity, due to its ability to oxidize 1,2-propanediol and to reduce glycolaldehyde, methylglyoxal and hydroxyacetone into ethylene glycol, lactaldehyde and 1,2-propanediol, respectively.

MDH1 catalyzes the reversible oxidation of malate to oxaloacetate, using the NAD/NADH cofactor system in the citric acid cycle. MDH1 is abundantly found in the cytoplasm and is involved in the malate-aspartate shuttle that functions in the metabolic coordination between cytosol and mitochondria. MDH1 regulates p53-dependent cell-cycle arrest and apoptosis in response to glucose deprivation.

Cytochrome b5 reductase 1 (CYB5R1) is a part of the flavoprotein pyridine nucleotide cytochrome reductase family. CYB5R1 is engaged in desaturation and elongation of fatty acids, cholesterol biosynthesis, drug metabolism, and, in erythrocyte, methemoglobin decrease.

Aminoacylase-1 is a cytosolic, homodimeric, zinc-binding enzyme that catalyzes the hydrolysis of acylated L-amino acids to L-amino acids and acyl group, and has been postulated to function in the catabolism and salvage of acylated amino acids. ACY1 has been assigned to chromosome 3p21.1, a region reduced to homozygosity in small-cell lung cancer (SCLC), and its expression has been reported to be reduced or undetectable in SCLC cell lines and tumors. The amino acid sequence of human aminoacylase-1 is highly homologous to the porcine counterpart, and ACY1 is the first member of a new family of zinc-binding enzymes.

TKT is a thiamine-dependent enzyme that takes part in the channeling of leftover sugar phosphates to glycolysis in the pentose phosphate pathway. Multiple alternatively spliced variants are known that encode the same protein.

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.

MTHFD2 plays a role as a homodimer which requires magnesium and inorganic phosphate. MTHFD2 has a pseudogene on chromosome 7 and owns 3 different enzymatic activities. Each of the activities catalyzes 1 of 3 sequential reactions in the interconversion of 1-carbon derivatives of tetrahydrofolate, which are substrates for methionine, thymidylate, and de novo purine syntheses.

GMDS is a member of the GDP-mannose 4,6-dehydratase family. GMDS uses NADP as a cofactor to catalyze the conversion of GDP-mannose to GDP-4-keto-6-deoxymannose. Defects in the gene encoding GMDS cause TRAIL (tumor necrosis factor-related apoptosis-inducing ligand)-induced apoptosis.

Acyl-CoA Thioesterase 8 (ACOT8) is a group of enzymes which catalyze the hydrolysis of acyl-CoAs to the free fatty acid and coenzyme A (CoASH), granting the potential to regulate intracellular levels of acyl-CoAs, free fatty acids and CoASH. ACOT8 mediate Nef-induced down-regulation of CD4. ACOT8 contends with BAAT (Bile acid CoA: amino acid N-acyltransferase) for bile acid-CoA substrate (such as chenodeoxycholoyl-CoA). ACOT8 prefers medium-length fatty acyl-CoAs.

ALDH2 is part of the aldehyde dehydrogenase family of proteins which catalyze the chemical transformation from acetaldehyde to acetic acid. ALDH2 is the second enzyme of the major oxidative pathway of alcohol metabolism. ALDH2 has 2 major liver isoforms: cytosolic and mitochondrial, which differ by their electrophoretic mobilities, kinetic properties, and subcellular localizations. Nearly all Caucasians have 2 major isozymes, whereas roughly 50% of Orientals have only the cytosolic isozyme, omitting the mitochondrial isozyme. The extremely higher rate of acute alcohol intoxication with Orientals compared to Caucasians is due to the fact of the absence of mitochondrial isozyme. ALDH2 has a low Km for acetaldehydes, and is localized in mitochondrial matrix.

Dihydrofolate reductase (DHFR) is an enzyme that reduces dihydrofolic acid to tetrahydrofolic acid, with NADPH as electron donor that can be converted to the kinds of tetrahydrofolate cofactors applied in 1-carbon transfer chemistry. DHFR converts dihydrofolate into tetrahydrofolate, which is a methyl group shuttle required for the de novo synthesis of purines, thymidylic acid, and specific amino acids. Even though the functional DHFR gene is mapped to chromosome 5, numerous intronless processed pseudogenes or dihydrofolate reductase-like genes are identified on separate chromosomes. DHFR deficiency is associated with megaloblastic anemia. DHFR knockdown plays a role in the anticancer activity of 2-hydroxyoleic acid. DHFR gene insertion/deletion polymorphism is linked to variation in serum and red blood cell folate concentrations in women.

BLVRB (EC 1.3.1.24) catalyzes electron transfer from reduced pyridine nucleotides to flavins as well as methylene blue, pyrroloquinoline quinone, riboflavin, or methemoglobin. BLVRB is involved in protecting cells from oxidative damage or in regulating iron metabolism. BLVRB converts biliverdin to bilirubin in the liver, converting a double-bond between the second and third pyrrole ring into a single-bond. BLVRB plays a role as in human erythrocytic heme catabolic pathway and most mammalian species. Biliverdin reductase is abundantly expressed in kidney, spleen, liver and brain as well as at lower levels in the thymus and minimal levels being detected in testis.

Napsin A Aspartic Peptidase, also known as NAPSA is a member of the peptidase A1 family. NAPSA is involved in the processing of pneumocyte surfactant precursors. Furthermore the activation peptides of aspartic proteinases take part as inhibitors of the active site. These peptide segments/pro-parts are considered essential for correct folding, targeting, as well as control of the activation of aspartic proteinase zymogens. The pronapsin A gene is expressed mostly in lung and kidney. In addition, NAPSA translation product is expected to be a fully functional, glycosylated aspartic proteinase precursor which contains an RGD motif as well as an additional 18 residues at its C-terminus.

Aldolase C Fructose-Bisphosphate (ALDOC) belongs to the class I fructose-bisphosphate aldolase family. ALDOC is a glycolytic enzyme which catalyzes the reversible aldol cleavage of fructose-1,6-biphosphate and fructose 1-phosphate to dihydroxyacetone phosphate and either glyceraldehyde-3-phosphate or glyceraldehydes respectively. ALDOC is expressed exclusively in the hippocampus and Purkinje cells of the brain.

N-alpha-acetyltransferase 50 (NAA50) consists of 169 amino acid cytoplasmic protein belonging to the acetyltransferase family and GNAT subfamily. NAA50 is a likely catalytic component of the ARD1A-NARG1 complex which displays alpha acetyltransferase activity. NAA50 has also been shown to interact with MAK10 and is encoded by a gene that maps to human chromosome 3q13.2.

Arylsulfatase A (ARSA) hydrolyzes cerebrosidesulfate to cerebroside and sulfate. ARSA is inhibited by phosphate. The phosphate develops a covalent bond with the active site 3-oxoalanine. ARSA gene defects cause metachromatic leucodystrophy (MLD), a progressive demyelination disease which results in various neurological symptoms and ultimately death.

Neuron-specificenolase also caled NSE is a glycolytic isoenzyme which is situated in central and peripheral neurons and neuroendocrine cells. Enolase-2 is released into the CSF when neural tissue is injured. Neoplasms derived from neural or neuroendocrine tissue release Enolase-2 into the blood. Enolase-2 is a useful substance that has been detected in patients with certain tumors, such as neuroblastoma, small cell lung cancer, medullary thyroid cancer, carcinoid tumors, pancreatic endocrine tumors, and melanoma. ENO2 is 1 of the 3 enolase isoenzymes found in mammals. ENO2 isoenzyme, is found in mature neurons and cells of neuronal origin. An exchange from alpha enolase to gamma enolase occurs in neural tissue during development in rats and primates.

G6PD is the rate-limiting enzyme of the pentose phosphate pathway, a metabolic pathway that supplies reducing energy to cells by maintaining the level of NADPH. G6PD converts glucose-6-phosphate into 6-phosphoglucono-?-lactone and at the same time produces NADPH. The NADPH maintains the level of glutathione in these cells that helps protect the red blood cells against oxidative damage. G6PD deficiency causes acute hemolytic anemia, neonatal jaundice or acute hemolysis. G6PD is a cytosolic enzyme encoded by an X-linked gene whose main function is to produce NADPH, a crucial electron donor in the defense against oxidizing agents and in reductive biosynthetic reactions. G6PD produces pentose sugars for nucleic acid synthesis and is a main producer of NADPH reducing power.

Cysteine Conjugate-Beta Lyase Cytoplasmic also known as CCBL1 is a member of the class-I pyridoxal-phosphate-dependent aminotransferase family. CCBL1 catalyzes the irreversible transamination of the L-tryptophan metabolite L-kynurenine to form kynurenic acid (KA) it also metabolizes the cysteine conjugates of certain halogenated alkenes and alkanes to form reactive metabolites. Furthermore, CCBL1 catalyzes the beta-elimination of S-conjugates and Se-conjugates of L-(seleno) cysteine, resulting in the cleavage of the C-S or C-Se bond.

Deoxyuridine Triphosphatase (DUT) is a ubiquitous enzyme that functions in nucleotide metabolism. Deoxyuridine Triphosphatase, in the presence of magnesium ions, is responsible for hydrolyzing dUTP to dUMP and diphosphate. This reaction is imperative for keeping the intracellular dUTP concentration low so that uracil does not become incorporated into DNA. Extensive integration of uracil into DNA can eventually lead to cell death. This suggests that DUT is crucial for cell viability, further implying that it is a prospective target for anticancer therapy.

N-acetylneuraminate lyase (NPL) is an enzyme which catalyzes the chemical reaction (N-acetylneuraminate ->N-acetyl-D-mannosamine + pyruvate). NPL is a member of a family of lyases, specifically the oxo-acid-lyases, which cleave carbon-carbon bonds. NPL participates in amino sugars metabolism.

Aspartylglucosaminidase, also known as AGA, takes part in the catabolism of Nlinked oligosaccharides of glycoproteins. AGA is a protein coding gene which cleaves asparagine from N-acetylglucosamines in the lysosomal breakdown of glycoproteins.

NSE is the ?? isoform of the glycolytic enzyme enolase and is expressed primarily in neurons, in normal and neoplastic neuroendocrine cells. NSE is a highly soluble cytoplasmic protein that is readily secreted into the CSF and serum following tissue damage. NSE shows neurotrophic and neuroprotective properties on a broad spectrum of central nervous system (CNS) neurons and binds in a calcium-dependent manner to cultured neocortical neurons promoting cell survival.

ACAT2 enzyme participates in lipid metabolism. ACAT2 takes part in lipoprotein assembly, catalyzing cholesterol esterification in mammalian cells. ACAT2 is an integral membrane protein that localizes to the endoplasmic reticulum of human intestinal cells. ACAT2 deficiency contributes to severe mental retardation and hypotonus.