Search results

GNMT is an enzyme that catalyzes the conversion of S-adenosyl-L-methionine with glycine to S-adenosyl-L-homocysteine and sarcosine. 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 (sarcosine) 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.

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.

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.

MMAB protein catalyzes the last step in the conversion of vitamin B(12) into adenosylcobalamin (AdoCbl), a vitamin B12 containing coenzyme for methylmalonyl-CoA mutase(MCM). Decreased MMAB activity leads to the inherited disorder vitamin B12 dependent methylmalonic aciduria linked to the cblB complementation group.

Arsenic Methyltransferase (AS3MT) catalyzes the transfer of a methyl group from S-adenosyl-L-methionine (AdoMet) to trivalent arsenical and may have a role in arsenic metabolism. AS3MT methylates arsenite to produce methylarsonate, Me-AsO3H2, which is reduced by methylarsonate reductase to methylarsonite, Me-As(OH)2. Methylarsonite which is also a substrate, is transformed into the much less toxic complex dimethylarsinate (cacodylate), Me2As(O)-OH.

GAMT is a methyltransferase that transfers guanidoacetate to creatine, using S-adenosylmethionine as the methyl donor. Defects GAMT gene result in neurologic syndromes and muscular hypotonia, probably due to creatine deficiency and accumulation of guanidinoacetate in the brain of affected individuals. GAMT take parts in the two-step synthesis of creatine from the protein building blocks glycine, arginine, and methionine. GAMT takes part in supplying the energy for muscle contraction, and is in addition a significant player in nervous system functioning. GAMT is active in the liver, pancreas, and kidne.

DNA Cytosine-5--Methyltransferase 3-Like (DNMT3L) is a nuclear protein with similarity to DNA methyltransferases, but is not believed to act as a DNA methyltransferase since it doesn’t contain the amino acid residues needed for methyltransferase activity. Nevertheless, DNMT3L stimulates de novo methylation by DNA cytosine methyltransferase 3 alpha and is assumed to be required for the formation of maternal genomic imprints. DNMT3L also mediates transcriptional repression as a result of interaction with histone deacetylase 1. DNMT3L is a catalytically inactive regulatory factor of DNA methyltransferases, which is vital for the function of DNMT3A and DNMT3B. DNMT3L activates DNMT3A and DNMT3B by binding to their catalytic domain. Furthermore, DNMT3L accelerates the binding of DNA and AdoMet to the methyltransferases and dissociates from the complex after DNA binding to the methyltransferases.

Queuine TRNA-Ribosyltransferase 1 also known as QTRT1 is a member of the queuine tRNA-ribosyltransferase family. QTRT1 interacts with QTRTD1 to form an active queuine tRNA-ribosyltransferase. Furthermore, QTRT1 exchanges queuine for the guanine at the wobble position of tRNAs with GUN anticodons (tRNA-Asp, -Asn, -His and -Tyr), in this manner forming the hypermodified nucleoside queuosine (Q) (7-(((4,5-cis-dihydroxy-2-cyclopenten-1-yl)amino)methyl)-7-deazaguanosine).

Thymidylate synthase catalyzes the methylation of deoxyuridylate to deoxythymidylate using 5,10-methylenetetrahydrofolate as a cofactor which maintains the dTMP (thymidine-5-prime monophosphate) pool vital for DNA replication and repair. Thymidylate synthase plays an important role as a cancer chemotherapeutic agent. Thymidylate synthase is the primary site of action for 5-fluoro-2-prime-deoxyuridine and several folate analogs.

GSTZ1 is part of the glutathione S-transferase super-family which encodes multifunctional enzymes vital in the detoxification of electrophilic molecules, including carcinogens, mutagens, and several therapeutic drugs, by conjugation with glutathione. GSTZ1 participates in the catabolism of phenylalanine and tyrosine. Thus defects in GSTZ1 cause harsh metabolic disorders including alkaptonuria, phenylketonuria and tyrosinaemia. GSTZ1 is a bifunctional protein which has minimal glutathione-conjugating activity with 7-chloro-4-nitrobenz-2-oxa-1,3-diazole and maleylacetoacetate isomerase activity. GSTZ1 has low glutathione peroxidase activity with T-butyl and cumene hydroperoxides. GSTZ1 catalyzes the glutathione dependent oxygenation of dichloroacetic acid to glyoxylic acid.

Glutathione S-transferase or GST, stands for a large family of detoxification proteins and enzymes. Glutathione S-transferase catalyzes glutathione reaction and an acceptor molecule to create S-substituted glutathione (S stands for sulfur). By this reaction, a large variety of compounds, for example therapeutic drugs, carcinogens & oxidative stress products, transformed. Glutathione S-transferase acts as a transport protein by binding toxins and acts as a transport protein. At first, the protein was isolated from Schistosomajaponicum, nowadays it is isolated from E. coli bacteria.

Tissue plasminogen activator (abbreviated PLAT or tPA) is a secreted serine proteasewhich converts the proenzymeplasminogento plasmin, a fibrinolyticenzyme. Plasminogen is synthesized as a single chain which is cleaved by PLAT into the two chain disulfide linked plasmin.
This enzyme plays a role in cell migrationand tissue remodeling. Increased enzymatic activity causes hyperfibrinolysis, which manifests as excessive bleeding; decreased activity leads to hypofibrinolysiswhich can result in thrombosisor embolism.

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.

Glutathione S-transferase Mu 2 (GSTM2) belongs to the glutathione s-transferase (GST) family of proteins. GSTM2 is a glutathione S-transferase that belongs to the mu class. There are 8 families of GST proteins, specifically: alpha, kappa, mu, omega, pi, sigma, theta and zeta, each of which is composed of proteins that have various functions throughout the cell. The mu class of enzymes functions in the detoxification of electrophilic compounds, including carcinogens, therapeutic drugs, environmental toxins and products of oxidative stress, by conjugation with glutathione. The genes encoding the mu class of enzymes are structured in a gene cluster on chromosome 1p13.3 and are proven to be highly polymorphic. These genetic variants can change an individual''s susceptibility to carcinogens and toxins as well as have an effect on the toxicity and efficacy of several drugs.

MGMT is an enzyme that repairs O-6-methylguanine, a mutagenic DNA base damaged by endogenous and environmental alkylating agents and takes part in the cellular defense against the biological effects of O-6-methylguanine in DNA. MGMT repairs alkylated guanine in DNA by stoichiometrically transferring the alkyl group at the O-6 position to a cysteine residue in the enzyme. abnormal MGMT expression correlates with the prognosis in human solid cancers. MGMT decrease of expression is correlated with methylation. The human MGMT is a negative regulator of estrogen receptor-mediated transcription upon alkylation DNA damage. MGMT promoter hypermethylation plays an important role in the early steps of colorectal carcinogenesis. Abnormal promoter hypermethylation of MGMT gene is associated with oral squamous cell carcinomas.

METTL21A, which is a part of the methyltransferase superfamily, is a Protein-lysine methyltransferase that in vitro methylates HSPA1, HSPA5 and HSPA8.

The AsnRS enzyme is a member of the ligases family, specifically those forming carbon-oxygen bonds in aminoacyl-tRNA and related compounds. An asparagine-tRNA ligase is an enzyme which catalyzes the chemical reaction: ATP + L-asparagine + tRNAAsn AMP + diphosphate + L-asparaginyl-tRNAAsn. The three substrates of the AsnRS enzyme are ATP, L-asparagine, and tRNA(Asn), whereas its three products are AMP, diphosphate, and L-asparaginyl-tRNA(Asn).

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.

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.

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.

GGCT is a member of the family of transferases, specifically the aminoacyltransferases. GGCT protein catalyzes the formation of 5-oxoproline from gamma-glutamyl dipeptides and takes an important part in glutathione homeostasis. GGCT induces release of cytochrome c from mitochondria with resultant induction of apoptosis.

Renalase (RNLS) is a flavin adenine dinucleotide-dependent amine oxidase which is secreted into the blood from the kidney. RNLS acts as a hormone which metabolizes circulating catecholamines that have an active role in the sympathetic and parasympathetic nervous systems. High catecholamine concentration activates plasma RNLS and promotes its secretion and synthesis.

N-6 Adenine-Specific DNA Methyltransferase 1, also known as N6AMT1 is part of the methyltransferase family. N6AMT1 is implicated in the methylation of release factor I during translation termination. In addition, N6AMT1 is involved in converting the arsenic metabolite monomethylarsonous acid to the less toxic dimethylarsonic acid.

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.