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Polypeptide N-Acetylgalactosaminyltransferase 1 (Galnt1) , is part of the UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase (GalNAc-T) family of enzymes. The initial reaction in O-linked oligosaccharide biosynthesis is catalyzed by Glant1, the transfer of an N-acetyl-D-galactosamine residue to a serine or threonine residue on the protein receptor. Moreover, Galnt1 is implicated in the glycosylation of proteins vital for bone formation for instance osteopontin and bone sialoprotein.

DYNLL1 is a protein that cooperates with NOS1 causing NOS1 inhibition. Binding of DYNLL1 weakens NOS1 (Neuronal nitric oxide synthase) dimer, a conformation needed for activity, and it regulates several biologic processes through its effects on nitric oxide synthase activity. DYNLL1 is a ubiquitously expressed protein that demonstrates high expression in testis and moderate expression in brain.

XYLT2 or Xylosyltransferase 2 is an enzyme which is expressed in ubiquitous and is part of the glycosyltransfe-rases family. XYLT2 promotes proteoglycans formation by attaching GAG chains to the substrate protein via transfer of xylose molecule from the donor (nucleoside diphosphate) to the protein’s serine residues. XYLT2 is present in the ER and the cis part of the Golgi, furthermore the protein is released to the extracellular matrix.

MAT2A is an important enzyme in cellular metabolism and catalyzes the formation of S-adenosylmethionine (SAMe) from L-methionine and ATP. MAT2A is expressed in extrahepatic tissues. In liver, MAT2A expression associates with growth, dedifferentiation, and cancer. NF-kappa B and AP-1 are necessary for basal MAT2A expression in HepG2 cells and mediate the increase in MAT2A expression in response to TNF-alpha. Up-regulation of MAT2A provides growth improvement and s-adenosylmethionine and methylthioadenosine thus can block mitogenic signaling in colon cancer cells. Lower expression of both MAT2A and MAT2beta and interfere with leptin signaling in liver cancer cells.

BPHL is a Serine hydrolase that is a part of the AB hydrolase superfamily which catalyzes the hydrolytic activation of amino acid ester prodrugs of nucleoside analogs. BPHL is expressed large quantities in liver and kidney and in minor quantities in heart, intestine and skeletal muscle. BPHL takes part in detoxification processes and is a specific alpha-amino acid ester hydrolase which favors small, hydrophobic, and aromatic side chains and does not have a strict necessity for the leaving group except for favoring a primary alcohol.

Antioxidant enzyme Glutathione S- Transferase (GST) is thought to do the primary cellular defense mechanism against reactive oxygen species. GST reduces lipid hydroperoxides through its Se-independent glutathione peroxidase activity. The enzyme also detoxifies lipid peroxidation end products such as 4-hydroxynonenal (4-HNE).
The soluble GST is a 26 kDa protein which occurs as a dimer in all aerobic organisms. Each monomer has two domains, one that binds GSH and is an /-structure similar to thioredoxin and the other, all helical, that binds the hydrophobic substrate. The GST -fusion protein expression system is a widely used recombinant protein expression system that allows a peptide or a regulatory protein domain to be expressed as a fusion to the C-terminus of Schistosoma japonicum GST. Fusion proteins also possess GST -enzymatic activity and can undergo dimerization similar to in vivo. The fusion protein can be purified via GST -affinity column chromatography. In most cases, the desired peptides or domains are removed from GST by applying a specific protease that recognizes and cleaves the linker between the protein domain and GST. The technique has been widely used to generate different kinds of proteins for crystallization, molecular immunology studies, the production of vaccines and studies involving protein-protein and protein-DNA interactions.

Glutaminyl-Peptide Cyclotransferase, also known as QPCT is a member of the glutaminyl-peptide cyclotransferase family. QPCT is responsible for the biosynthesis of pyroglutamyl peptides. Furthermore, QPCT is partial against acidic and tryptophan residues adjacent to the N-terminal glutaminyl residue and a lack of importance of chain length following the second residue. QPCT catalyzes N-terminal pyroglutamate formation, also in vitro, it catalyzes pyroglutamate formation of N-terminally truncated form of APP amyloid-beta peptides [Glu-3]-beta-amyloid.

GARS is an (alpha)2 dimer which is a member of the class II family of tRNA synthetases. GARS is a glycyl-tRNA synthetase, one of the aminoacyl-tRNA synthetases which charge tRNAs with their cognate amino acids. GARS catalyzes the attachment of glycine to tRNA(Gly). In addition, GARS is able to produce diadenosine tetraphosphate (Ap4A), which is a universal pleiotropic signaling molecule required for cell regulation pathways, by direct condensation of two ATPs. GARS has been demonstrated to be a target of autoantibodies in the human autoimmune diseases, polymyositis or dermatomyositis.

HIBCH enzyme is in charge of hydrolysis of both HIBYL-CoA and beta-hydroxypropionyl-CoA. Damages in the HIBCH gene linked to 3-hyroxyisobutyryl-CoA hydrolase deficiency. Multiple transcript variants exist as a result of alternative splicing.

Lysyl Oxidase also known as LOX is an extracellular copper enzyme which initiates the crosslinking of collagens and elastin. LOX catalyzes oxidative deamination of the epsilon-amino group in certain lysine and hydroxylysine residues of collagens and lysine residues of elastin. Adding up to crosslinking extracellular matrix proteins, LOX plays a part in tumor suppression. Moreover, defects in LOX are the cause of autosomal recessive cutis laxa type I, CL type I. Two transcript variants encoding dissimilar isoforms have been found for LOX.

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.

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.

E2 17-beta-dehydrogenase 8 (HSD17B8) is a member of the short-chain dehydrogenases/reductases (SDR) family. In mice, the HSD17B8 protein is a 17-beta-hydroxysteroid dehydrogenase which can regulate the concentration of biologically active estrogens and androgens. HSD17B8 is preferentially an oxidative enzyme and inactivates E2, testosterone, and DHT. However, the HSD17B8 enzyme has some reductive activity and can synthesize E2 from E1. HSD17B8 may have a role in biosynthesis of fatty acids in mitochondria.

Sepiapterin Reductase is an aldo-keto reductase that catalyzes the NADPH-dependent reduction of pteridine derivatives and is essential in the biosynthesis of BH4. Mutations in Sepiapterin Reductase gene result in DOPA-responsive dystonia due to sepiaterin reductase deficiency defined by the presence of sustained involuntary muscle contractions, often leading to abnormal postures. Sepiapterin reductase is part of the short-chain dehydrogenase/reductase family which reduces exogenous carbonyl compounds as well as phenylpropanedione. Sepiapterin reductase is an important enzyme for the biosynthesis of tetrahydrobiopterin, an necessary cofactor for aromatic amino acid hydrolases together with tyrosine hydroxylase, the rate-limiting enzyme in dopamine synthesis.

GOT2 is a pyridoxal phosphate-dependent enzyme which is found in cytoplasmic and inner-membrane mitochondrial forms, GOT1 and GOT2. GOT2 is invloved in amino acid metabolism and the urea and tricarboxylic acid cycles. The 2 enzymes are homodimeric and demonstrate close homology.

Dopa decarboxylase is a homodimeric, pyridoxal phosphate dependent enzyme.
Dopa decarboxylase is involved in 2 metabolic pathways, synthesizing 2 significant neurotransmitters the take part in numerous clinical disorders, including Parkinson’s disease. Dopa decarboxylase is located in different areas of the brain and is mostly found in basal ganglia. Dopa decarboxylase catalyzes the decarboxylation of L-3,4-dihydroxyphenylalanine (DOPA) to dopa, L-5-hydroxytryptophan to serotonin and L-tryptophan to tryptamine. Defects in Dopa decarboxylase leads to aromatic L-amino-acid decarboxylase deficiency (AADCD). AADCD deficiency is an inborn error in neurotransmitter metabolism that causes combined serotonin and catecholamine deficiency.

CA14 is a part of the Carbonic anhydrases family. Carbonic anhydrases (CAs) are a large family of zinc metalloenzymes which catalyze the reversible hydration of carbon dioxide. They present wide variety in tissue distribution and in their subcellular localization. CA14 is a type I membrane protein which shares highest sequence similarity with the other transmembrane CA isoform, CA XII. Nevertheless, they have different patterns of tissue-specific expression and therefore take different physiologic parts.

GAPDH is a catalytic enzyme normally known to play a role in glycolysis. GAPDH exists as a tetramer composed of 36-kDa subunits and has a range of intracellular functions. GAPDH catalyzes the reversible reduction of 1,3-bisphosphoglycerate to glyceraldehyde 3-phosphophate in the presence of NADPH. Besides functioning as a glycolytic enzyme in cytoplasm, GAPDH has function in intracellular processes such as membrane fusion, microtubule bundling, phosphotransferase activity, nuclear RNA export, DNA replication and DNA repair. GAPDH catalyzes a vital energy-yielding step in carbohydrate metabolism, the reversible oxidative phosphorylation of glyceraldehyde-3-phosphate in the presence of inorganic phosphate and nicotinamide adenine dinucleotide (NAD). The enzyme exists as a tetramer of identical chains.

HPRT1 has a main part in the generation of purine nucleotides through the purine salvage pathway. HPRT1 primarily functions to salvage purines from degraded DNA to renewed purine synthesis. Therefore, it performs as a catalyst in the reaction between guanine and phosphoribosyl pyrophosphate to form GMP.

NADH Dehydrogenase 1 Beta Subcomplex 4 (NDUFB4) is a member of the complex I NDUFB4 subunit family. NDUFB4 is a non-catalytic subunit of the multisubunit NADH:ubiquinone oxidoreductase, which is the first enzyme complex in the mitochondrial electron transport chain (complex I). Mammalian complex I is comprised of 45 different subunits and transfers electrons from NADH to ubiquinone.

ST6GAL1 also known as ST6 Beta-Galactosamide Alpha-2,6-Sialyltranferase 1, is part of the glycosyltransferase family 29. ST6GAL1 is a type II membrane protein which catalyzes the transfer of sialic acid from CMP-sialic acid to galactose-containing substrates. Furthermore, ST6GAL1 is normally found in the Golgi however it can be proteolytically processed to a soluble form, ST6GAL1 is also involved in the generation of the cell-surface carbohydrate determinants as well differentiation antigens HB-6, CD75, and CD76.

D-Tyrosyl-tRNA Deacylase 1 (DTD1) is a member of the DTD family. DTD1 hydrolyzes D-tyrosyl-tRNA(Tyr) into D-tyrosine and free tRNA(Tyr). DTD1 may be a defense mechanism against a damaging effect of D-tyrosine. DTD1 is an ATPase involved in DNA replication, which may facilitate loading of CDC45 onto pre-replication complexes. The DTD1 protein localizes to the DUE (DNA unwinding elements) of active replication origins. DTD1 is expressed in numerous adult and fetal tissues, with the highest levels in the testis, ovary, spleen and in the adult and fetal brain. DTD1 might be a risk factor for AIA (aspirin-intolerant asthma) by catalyzing the hydrolysis of D-tryptophan and interacting with the tyrosyl-tRNA synthetase (tyrRS) enzyme that promotes a pro-inflammatory phenotype.

GOT2 is a pyridoxal phosphate-dependent enzyme which is found in cytoplasmic and inner-membrane mitochondrial forms, GOT1 and GOT2. GOT2 participates in amino acid metabolism and the urea and tricarboxylic acid cycles. Both enzymes are homodimeric and demonstrate close homology.

NAA10 is a member of the acetyltransferase family. NAA10 interacts with NAA15, HIF-1 and with the ribosome. In its binding to HIF-1, NAA10 functions as a protein acetyltransferase by regulating its stability. In various cell lines, NAA10 is downregulated in response to hypoxia. NAA10 is expressed during the course of the development of the brain.