Search results

Celiac disease is an enteropathy that is characterized by intestinal lesions of variable severity. Tissue-type transglutaminase (tTG) is believed to be the predominant autoantigen for celiac disease and the corresponding autoantibodies show higher sensitivity and specificity than anti-gliadin antibodies. Highly pure recombinant human tTG is now available to replace the traditionally used tTG fraction from guinea pig.
Tissue-type transglutaminase antigens have been specifically modified for improved handling: exchange of an active site amino acid eliminates the protein cross-linking activity of the enzyme, while maintaining the native three-dimensional structure and the enzyme's secondary GTPase activity. This engineering assures reproducible properties of the antigen preparations through the absence of variable and ill-defined covalent aggregates of tTG antigen and host cell proteins.

Phosphoserine aminotransferase (PSAT1) catalyzes the conversion of 3-phosphohydroxypyruvate into 3-phosphoserine which is dephosphorylated consequently by phosphoserine phosphatase to form L-serine. PSAT1 is probably a phosphoserine aminotransferase, based on similarity to proteins in mouse, rabbit, and Drosophila. PSAT1 is expressed at high levels in the brain, liver, kidney and pancreas, and very weakly expressed in the thymus, prostate, testis and colon. Defects in the PSAT1 gene are the cause of phosphoserine aminotransferase deficiency (PSATD). PSATD is distinguished biochemically by low plasma and cerebrospinal fluid concentrations of serine and glycine and clinically by intractable seizures, acquired microcephaly, hypertonia, and psychomotor retardation.

tRNA aspartic acid methyltransferase 1 (TRDMT1) is a member of the C5-methyltransferase family. TRDMT1 specifically methylates cytosine 38 in the anticodon loop of tRNA(Asp). TRDMT1 is a protein responsible for the methylation of aspartic acid transfer RNA, particularly at the cytosine-38 residue in the anticodon loop. In addition, the TRDMT1 enzyme has residual DNA-(cytosine-C5) methyltransferase activity. TRDMT1 is expressed ubiquitously; however it has a higher expression in the testis, ovary and thymus and at much lower levels in the spleen, prostate, colon, small intestine, and peripheral blood leukocytes. Though similar in sequence and structure to DNA cytosine methyltransferases, the TRDMT1 gene is distinctive and extremely conserved in its function between taxa.

Aminomethyltransferase, mitochondrial isoform 1 (AMT) is a component of the glycine cleavage system termed T-protein. AMT reversibly catalyzes the degradation of the aminomethyl moiety of glycine attached to the lipoate cofactor of H-protein, leading to the production of ammonia, 5,10-methylenetetrahydrofolate, and dihydrolipoate-bearing H-protein in the presence of tetrahydrofolate.

Glutamyl-TRNA Amidotransferase, Subunit C also known as GATC allows the formation of properly charged Gln-tRNA(Gln) through the transamidation of misacylated Glu-tRNA(Gln) in the mitochondria. The reaction occurs in the attendance of glutamine and ATP through an activated gamma-phospho-Glu-tRNA(Gln). In addition, GATC is subunit of the heterotrimeric GatCAB amidotransferase (AdT) complex, composed of A (QRSL1), B (PET112) and C (GATC) subunits.

METTL1 is recognized as tRNA (guanine-N(7)-)-methyltransferase that is a part of the methyltransferase superfamily. METTL1 displays high sequence similarity to yeast ORF YDL201w and can be inactivated by phosphorylation. METTL1 protein has a conserved S-adenosylmethionine-binding motif and ccatalyzes the formation of N(7)-methylguanine at position 46 (m7G46) in tRNA.

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.

NAT1 is a member of the arylamine N-acetyltransferase family. NAT1 catalyzes N- or O-acetylation of heterocyclic and arylamine substrates in the detoxification of a large number of drugs. Several alleles triggering high levels of N-acetyltransferase activity were linked to colon and urinary bladder cancers, since NAT1 also bioactivate numerous known carcinogens. NAT1 aids metabolize drugs and other xenobiotics, and takes part in the detoxification of a plethora of hydrazine and arylamine drugs.

tRNA 2'-phosphotransferase 1 (TRPT1) is a member of the KptA/TPT1 family. TRPT1 catalyzes the last step of tRNA splicing, the transfer of the splice junction 2'-phosphate from ligated tRNA to NAD to produce ADP-ribose 1''-2'' cyclic phosphate. TRPT1 is broadly expressed; it is weakly or not expressed in the lung, spleen, small intestine and peripheral blood leukocytes.

Glycine amidinotransferase mitochondrial (GATM) is a mitochondrial enzyme which is a member of the amidinotransferase family. The GATM enzyme is involved in creatine biosynthesis, where it catalyzes the transfer of a guanido group from L-arginine to glycine, resulting in guanidinoacetic acid, the immediate precursor of creatine, which has an imperative role in energy metabolism in muscle tissues. GATM is significant in embryonic and central nervous system development. GATM gene mutations cause arginine:glycine amidinotransferase deficiency, an inborn error of creatine synthesis characterized by mental retardation, language impairment, and behavioral disorders.

PNMT is an enzyme located in the adrenal medulla and it catalyzes the final step of the catecholamine biosynthesis pathway. PNMT has beta-carboline 2N-methyltransferase activity. PNMT takes part in regulating epinephrine production. Glucocorticoid receptors form multimers of PNMT independent of the DNA binding domain. PNMT expression is regulated late in mouse gestation by AP2-alpha and glucocorticoids.

N-terminal Xaa-Pro-Lys N-methyltrasferase1, also known as NTMT1 belongs to the methyltransferase superfamily. NTMT1 catalyzesthe transfer of the methyl group from the S-adenosyl-l-methionine to the protein ?-amine, resulting in the formation of S-adenosyl-l-homocysteine and ?-N-methylated proteins. NTMT1 is a remarkable potential anticancer targetsince it is overexpressed in gastrointestinal cancers in addition to his essential function in cell mitosis.

This gene is a member of the ADAR (adenosine deaminase acting on RNA) family. Using site-specific adenosine modification, proteins encoded by these genes participate in the pre-mRNA editing of nuclear transcripts. The protein encoded by this gene, tRNA-specific adenosine deaminase 1, is responsible for the deamination of adenosine 37 to inosine in eukaryotic tRNA.

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.

ASMT is a member of the methyltransferase superfamily. ASMT participates in melatonin biosynthesis. ASMT Expressed in brain, retina and pineal gland, ASMT utilities to catalyze the final reaction in the synthesis of melatonin, particularly the conversion of S-adenosyl-L-methionine and N-acetylserotonin to S-adenosyl-Lhomocysteine and melatonin.

Glutathione S-transferase, also known as GST, is an antioxidant enzyme. It is the primary defense mechanism from reactive oxygen in the cell. The enzyme GST reduces hydroperoxides of lipids via a Se-independent glutathione peroxidase actions. GST detoxifies peroxidation of lipids bi-products, for example 4-hydroxynonenal.

NAT6 is an enzyme that catalyzes the transfer of acetyl groups from acetyl-CoA to acrylamines. NAT6 is located mainly in the cytoplasm and its activity has been recognized by its feasibility to acetylate the N-terminus of proteins using a ping-pong-like mechanism and by its substrate specificity. Given that the NAT6 gene maps to the chromosomal region 3p21.3, which includes at least one tumor suppressor gene, the function of NAT6 plays an important role in cancer.

Polypeptide N-Acetylgalactosaminyltransferase 1 (Galnt1) is a 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.

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.

NMNAT1 enzyme is vital for NAD biosynthesis, catalyzing the condensation of nicotinamide mononucleotide (NMN) or nicotinic acid mononucleotide (NaMN) with the AMP moiety of ATP to form NAD or NaAD. NMNAT1 is widely expressed with high levels in skeletal muscle, heart, liver and kidney. This protein appears to have the ability to protect against axonal degeneration following mechanical or toxic insults.

Lysine Methyltransferase 5A (KMT5A) is an enzyme which catalyzes both histones and non-histone proteins. KMT5A contributes to the maintenance of proper higher-order structure of DNA during mitosis. KMT5A takes part in cell-cycle-dependent transcriptional silencing and mitotic regulation in metazoans. KMT5A plays a role as a barrier to prevent cellular senescence through chromatinmediated regulation of senescence-associated metabolic remodeling. KMT5A mediates monomethylation of p53/TP53 at 'Lys-382', which leads to repress p53/TP53-target genes. The loss of KMT5A simultaneously stimulate nucleolar function and retinoblastoma protein-mediated mitochondrial metabolism.

MAT1A catalyzes a two-step reaction that involves the transfer of the adenosyl moiety of ATP to methionine to form S-adenosylmethionine and tripolyphosphate, which is subsequently cleaved to PPi and Pi. S-adenosylmethionine is the source of methyl groups for most biological methylations. MAT1A is found as a homotetramer (MAT I) or a homodimer (MAT III) whereas a third form, MAT II (gamma), is encoded by the MAT2A gene. Mutations in MAT1A gene are associated with methionine adenosyltransferase deficiency. MAT1A expression also correlates with a differentiated phenotype, whereas liver cells expressing MAT2A present a dedifferentiated phenotype and lowered AdoMet synthesis. Likewise, NFκB and TNFα cause a switch from MAT1A to MAT2A expression in human hepatocellular carcinoma (HCC), which facilitates cancer cell growth.

GNMT is an enzyme that catalyzes the conversion of S-adenosyl-L-methionine with glycine to S-adenosyl-L-homocysteine. GNMT is located in the cytoplasm and acts as a homotetramer. Defects in the GNMT gene causes of GNMT deficiency (hypermethioninemia). GNMT affects DNA methylation by regulating the ratio of S-adenosylmethionine to S-adenosylhomocystine and is involved in the detoxification pathway in liver cells. GNMT expression is diminished in human hepatocellular carcinoma (HCC). GNMT catalyzes the methylation of glycine by using s- adenosylmethionine (adomet) to form n-methylglycine with the concomitant production of s-adenosylhomocysteine (adohcy). GNMT plays an essential role in the regulation of tissue concentration of adomet and of metabolism of methionine.

OTC is a member of the ATCase/OTCase family. OTC has a key part in the urea cycle, catalyzing the second step in this pathway: the transformation of L-orthinine and carbamoyl phosphate to L-citrulline. In humans, the urea cycle is a vital pathway to detoxification of ammonia. Alterations in the gene encoding OTC are linked to the X-linked disorder OTCD (ornithine carbamoyltransferase deficiency). OTCD disorder of the urea cycle is characterized by hyperammonemia.