Other Enzymes

Ribophorin 2 (RPN2) is a dolichyl-diphosphooligosaccharide protein glycosyltransferase subunit 2. The Ribophorin 2 protein is part of an N-oligosaccharyl transferase complex which links high mannose oligosaccharides to asparagine residues found in the Asn-X-Ser/Thr consensus motif of nascent polypeptide chains. RPN2 is analogous in sequence to the yeast oligosaccharyl transferase subunit SWP1.

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.

RNHA is an endonuclease which specifically degrades the RNA of RNA-DNA hybrids. Localized to the nucleus, the RNHA protein mediates the removal of Okazaki fragment RNA primers which are present on the lagging strand during DNA replication. RNHA catalyzes the endonucleolytic cleavage of RNA to a 5'-phosphomonoester and is capable of binding magnesium or manganese as cofactors.

ME2 catalyzes the oxidative decarboxylation of malate to pyruvate, malat + NAD(P)+? pyruvate + CO2 + NAD(P)H+, and is found both in eukaryotic and prokaryotic cells. Three different isoforms of ME are known to be in mammalian tissues: a strictly cytosolic NADP+-dependent enzyme, an NADP+-dependent mitochondriail isoform, and a mitochondrial isoenzyme that is able to use both NAD+ and NADP+ but is more effective with NAD+. The mammalian isoforms size is about 62-64 kDa. A native size of 240,000 Da proposes a tetrameric structure for the active enzyme.
Mitochondrial NAD+-dependent ME 2 activity is seen in tissues that experience many cell divisions, like spleen, thymus, and the basal cells of the small intestinal mucosa. ME2 is also expressed all through the rapid cleavage stages of early Xenopus development. Activity for this isoform is low or nonexistent in brain, muscle, and normal and regenerating liver tissue from rat but was observed in rat adrenal cortex, pigeon and human skeletal muscle, and in heart muscle of some species. In addition, it is expressed in mitochondria of all tumor cells inspected to detain ascites tumors, hepatoma cells, and a variety of other tumors and transformed cell lines.

Ubiquinone biosynthesis protein COQ9 (COQ9) represents a mitochondrial ubiquinone biosynthesis gene. The COQ9 protein is likely required for biosynthesis of coenzyme Q10, since mutations at this locus have been linked with autosomal-recessive neonatal-onset primary coenzyme Q10 deficiency.

Glycogenin-1 (GYG1) is an enzyme involved in glycogen biosynthesis. GYG1 is the chief enzyme involved in glycogen polymerisation. Glycogenin-1 is vital for the function of self-glucosylates, using an inter-subunit mechanism, to form an oligosaccharide primer which acts as substrate for glycogen synthase. In addition, GYG1 has a role in regulating glycogen metabolism and the achievement of maximal glycogen levels in skeletal muscle. GYG1 mRNA and protein content and activity increase in the muscle during recovery from prolonged and exhaustive exercise. GYG1 is inactivated with glycogen catabolism which concurs with an increase in glycogenin gene expression as exercise and glycogenolysis advance. Glycogenin will remain covalently attached to the reducing end of the glycogen molecule.

Glucuronidase Beta (GUSB) is a lysosomal hydrolase which is taking part in the stepwise degradation of glucuronic acid-containing glycosaminoglycans and plays a significant role in the degradation of dermatan and keratin sulfates. GUSB is comprised of heparin sulfate, chondroitin sulfate and hyaluronan.

Carboxymethylenebutenolidase homolog (CMBL) is a cysteine hydrolase of the dienelactone hydrolase family which is highly expressed in the liver cytosol. CMBL is the human homolog of Pseudomonas dienelactone hydrolase, which is a protein that participates in the bacterial halocatechol degradation pathway. CMBL which preferentially cleaves cyclic esters activates medoxomil-ester prodrugs in which the medoxomil moiety is coupled with an oxygen atom. CMBL is inhibited by PCMB (p-chloromercuribenzoate) and is encoded by a gene which maps to human chromosome 5p15.2. CMBL can also activate beta-lactam antibiotics faropenem medoxomil and lenampicillin. CMBL is widely expressed, with the highest levels in the liver, followed by the kidney, small intestine and the colon.

Urokinase (UK) is a serine protease, which is one of biological plasminogen activators.
It is involved in a number of biological functions including fibrinolysis, embryogenesis, cell migration, tissue remodeling, ovulation, and wound healing.
It can be obtained from human urine or kidney cell culture.

Lysozymeis an antimicrobial enzyme produced by animals that are part of the innate immune system. Lysozyme is a glycoside hydrolase that catalyzes the hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in peptidoglycan, which is the major component of gram-positive bacterial cell wall.Lysozymes have primarily a bacteriolytic function - those in tissues and body fluids are associated with the monocyte-macrophage system and enhance the activity of immunoagents.

PRTN3 is a polymorphonuclear leukocyte serine protease which degrades elastin, fibronectin, laminin, vitronectin, and collagen types I, III, and IV (in vitro) and causes emphysema once managed by tracheal insufflation to hamsters.

Chitodextrinase is a unique membrane-bound endoenzyme. The chitodextrinase enzyme cleaves soluble oligomers, but not chitin, to the di- and trisaccharides. Chitodextrinase is unable to solubilize chitin, but it can catalyze the hydrolysis of high to low molecular weight soluble chitin oligosaccharides.

GlsA1 is a member of the great superfamily of serine-dependent beta-lactamases and penicillin-binding proteins which exist almost in every bacteria and eukaryotes and catalyze the hydrolytic deamidation of l-glutamine to l-glutamate and free NH4+.

Latexin enzyme is a carboxypeptidase A inhibitor that is highly expressed in the heart, prostate, ovary, kidney, pancrease, brain and colon. Latexin has no noticeable sequence resemblance with plant and parasite inhibitors, however it is related to a human putative tumor suppressor protein, TIG1. Latexin is down-regulated in the presenilin-1-deficient mouse brain, thus putatively playing a role in Alzheimer's disease.

Tryptase alpha/beta-1 (TPSAB1) is a tryptase which is the key neutral protease present in mast cells and is discharged upon the coupled activation-degranulation response of this cell type. TPSAB1 is enzymatically active only as a heparin-stabilized tetramer, and is resistant to all known endogenous proteinase inhibitors. TPSAB1 is implicated as a mediator in the pathogenesis of asthma and other allergic and inflammatory disorders.

Tryptase alpha/beta-1 (TPSAB1) is a tryptase which is the key neutral protease present in mast cells and is discharged upon the coupled activation-degranulation response of this cell type. TPSAB1 is enzymatically active only as a heparin-stabilized tetramer, and is resistant to all known endogenous proteinase inhibitors. TPSAB1 is implicated as a mediator in the pathogenesis of asthma and other allergic and inflammatory disorders.

DNA-directed RNA polymerase II subunit RPB11-b2 (POLR2J3) is a member of the eukaryotic RPB11 RNA polymerase subunit family. POLR2J (DNA-directed RNA polymerase II subunit J) exists in 3 variants POLR2J1 (RPB11-a), POLR2J2 (RPB11-b1), and POLR2J3 (RPB11-b2). POLR2J3 is a DNA-dependent RNA polymerase which catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates.

GALM is a main enzyme of carbohydrate metabolism catalysing the translation of beta-D-galactose to alpha-D-galactose. GALM is needed for normal galactose metabolism by preserveing the equilibrium of alpha and beta anomers of galactose. GALM is required for the production of complex oligosaccharides.

Ras GTPase-activating protein-binding protein 2 (G3BP2) is restricted to the plasma membrane and endocytic compartments and controls a fast endocytic recycling pathway. G3BP2 may be a scaffold protein which might be involved in mRNA transport.

G3BP1 belongs to the heterogeneous nuclear RNA-binding proteins and is also an element of the Ras signal transduction pathway. G3BP1 is one of the DNA-unwinding enzymes that favors partially unwound 3'-tailed substrates and is also able to unwind partial RNA/DNA and RNA/RNA duplexes in an ATP-dependent fashion. G3BP1 binds specifically to the Ras-GTPase-activating protein by associating with its SH3 domain. In addition, G3BP1 cleaves exclusively between cytosine and adenine and cleaves MYC mRNA preferentially at the 3'-UTR.

Fucosyltransferase 3 (FUT3) catalyzes alpha-1, 3 and alpha-1, 4 glycosidic linkages which take part in the expression of Vim-2, Lewis A, Lewis B, sialyl Lewis X and Lewis X/SSEA-1 antigens. FUT3 takes part in blood group Lewis determination; Lewis-positive (Le+) individuals have an active enzyme while Lewis-negative (Le-) individuals have an inactive enzyme. FUT3 also operates on the corresponding 1, 4-galactosyl derivative, creating1, 3-L-fucosyl links.

Tryptophanase, also known as tnaA, catalyzes chemical reaction using 2 substrates which are L-tryptophan and H2O. tnaA protein's three products are indole, pyruvate, and NH3.

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.

IYD is an enzyme that catalyzes the oxidative NADPH-dependent deiodination of both mono- and diiodotyrosine although acts more efficiently on monoiodotyrosine. The N-terminus of Iodotyrosine Deiodinase , also known as IYD, plays a role as a membrane anchor. IYD acts during the hydrolysis of thyroglobulin to liberate iodide, which then reenter the hormone-producing pathways.

Deoxyribodipyrimidine photo-lyase (phrB) is a member of the DNA photolyase class-1 family. phrB takes part in repair of UV radiation-inducedDNA damage. phrB catalyzes the light-dependent monomerization (300-600 nm) of cyclobutyl pyrimidinedimers (in cis-syn configuration), which are formed between closest bases on the same DNA strand uponexposure to ultraviolet radiation.

PGLS is an enzyme in the second step pentose phosphate pathway. 6-Phosphogluconolactonase is crucial for the synthesis of nucleotide sugars and NADPH, the key cause for decreasing power. PGLS transforms 6-phosphogluconolactone to 6-phosphogluconate.

Catalase (CAT) is a key antioxidant enzyme in the body’s defense against oxidative stress. Furthermore, Catalase is a heme enzyme which is present in the peroxisome of virtually all aerobic cells. Catalase converts the reactive oxygen species hydrogen peroxide to water and oxygen and thus diminishes the toxic effects of hydrogen peroxide. Catalase stimulates growth of cells including T-cells, B-cells, myeloid leukemia cells, melanoma cells, mastocytoma cells and normal and transformed fibroblast cells. Catalase gene polymorphisms are linked with decreases in catalase activity nevertheless, to date, acatalasemia is the only disease known to be caused by the CAT gene.

Progastricsin-C (PGC) is an aspartic proteinase which is synthesized in the gastric mucosa as inactive precursors. PGC is a part of the peptidase family A1 and contains a prosegment which is responsible for stabilizing the inactive form and preventing the entrance of the substrate to the active site. PGC is used as a biomarker for various gastric diseases including Helicobacter pylori related gastritis. PGC is also hydrolyzes various proteins.

TATDN3 is a member of the great superfamily of metalloenzymes. TATDN3 binds 2 divalent metal cations per subunit.

FBL is a significant small nucleolar protein in eukaryotes, which has an essential role in pre-rRNA processing during ribosomal biogenesis. Fibrillarin is a component of several ribonucleoproteins including a nucleolar small nuclear ribonucleoprotein (SnRNP) and one of the two classes of small nucleolar ribonucleoproteins (snoRNPs). Fibrillarin contains an N-terminal repetitive domain which is rich in glycine and arginine residues, like fibrillarins in other species. Fibrillarin’s central region is similar to an RNA-binding domain and contains an RNP consensus sequence. FBL is linked to the U3, U8, and U13 small nuclear RNAs and is positioned in the dense fibrillar component (DFC) of the nucleolus. Antisera from roughly 8% of humans with the autoimmune disease scleroderma recognize fibrillarin.

Biotinidase also known BTD, belongs to the nitrilase superfamily, which contains 12 families of nitrilases, amidases, carbamylases, and N-acyltrasferases. BTD catalyzes the hydrolysis of biocytin, the product of biotin-dependent carboxylase degradation, to biotin and lysine. BTD has a vital regulatory part in chromatin/DNA function. Mutations in BTD protein lead to Biotinidase deficiency.

PAPPA is a large zinc binding protein, which plays a role as a metalloprotease and specifically cleaves IGFBP-4 and IGFBP-5, resulting in release of bound IGF. PAPP-A regulates IGF bioactivity in various biological systems, including the human ovary and cardiovascular systems. PAPP A levels were higher in patients with unstable angina or acute myocardial infarction. PAPPA is also involved in local proliferative processes such as wound healing and bone remodeling. Moreover, PAPP-A is produced in high concentrations during pregnancy and is released into the maternal circulation. In placenta, PAPP A is expressed in X cells in septa and anchoring villi, and in syncytiotrophoblasts in the chorionic villi.

PAPPA is a large zinc binding protein, which acts as a metalloprotease and specifically cleaves IGFBP-4 and IGFBP-5, resulting in release of bound IGF. PAPP-A can also act as a regulator of IGF bioactivity in a number of biological systems, including the human ovary and cardiovascular systems. It was shown that PAPP A levels are elevated in patients with unstable angina or acute myocardial infarction. Furthermore, PAPPA is believed to be involved in local proliferative processes such as wound healing and bone remodeling. Moreover, PAPP-A is produced in high concentrations during pregnancy and is released into the maternal circulation. In placenta, PAPP A is expressed in X cells in septa and anchoring villi, and in syncytiotrophoblasts in the chorionic villi.
Lower levels of PAPPA are found in an array of other tissues including kidney, myometrium, endometrium, ovaries, breast, prostate, bone marrow, colon, fibroblasts and osteoblasts. PAPP-A is present in serum and placenta during pregnancy; with levels increasing throughout pregnancy. Low levels of PAPP A are associated with a number of foetal chromosomal abnormalities, as well as pre-eclampsia and stillbirth.
PAPPA levels may be a potentially highly specific marker for heart disease.
PAPP-A proteolytic activity is inhibited by targeting substrate exosite binding.

STYX is a member of the protein-tyrosine phosphatase family. STYX has a Gly residue instead of a conserved Cys residue in the dsPTPase catalytic loop which renders it catalytically inactive as a phosphatase. Nevertheless, the binding pocket is adequately preserved to bind phosphorylated substrates, and possibly protect them from phosphatases. STYX takes part in spermiogenesis.

Serine/threonine/tyrosine-interacting protein (STYX) is a member of the protein-tyrosine phosphatase family. STYX contains a Gly residue instead of a conserved Cys residue in the dsPTPase catalytic loop which makes it catalytically inactive as a phosphatase. On the other hand, the binding pocket is adequately preserved to bind phosphorylated substrates, and may protect them from phosphatases. STYX may have a role in spermiogenesis. STYX is a possible pseudophosphatase.

Obg-like ATPase 1 (OLA1) acts as a negative regulator of the cellular antioxidant response independent of transcriptional processes. OLA1 curbs the antioxidant response via nontranscriptional mechanisms. OLA1 hydrolyzes ATP, and can also hydrolyze GTP with lower efficiency. OLA1 is clearly down-regulated by DNA damage-inducing agents. OLA1 is expressed in all tissues; however it is more abundant in the testis, liver, lung, and brain. OLA1 is overexpressed in a number of malignancies, including cancers of the colon, rectum, ovary, lung, stomach, and uterus.

Elastase-2 (ELANE) is a serine protease that belongs to the chymotrypsin family. ELANE breaks down elastin, an elastic fiber together with collagen and controls the mechanical properties of connective tissue. The neutrophil form breaks down the Outer membrane protein A (OmpA) of E. coli and other Gram-negative bacteria. ELANEis inhibited by the acute-phase protein alpha 1-antitrypsin (A1AT), which binds almost irreversibly to the active site of elastase and trypsin.A1AT is usually secreted by the liver cells into the serum. A1AD leads to uninhibited destruction of elastic fiber by elastase.

BAT1 belongs to the DEAD box family of RNA-dependent ATPases that mediate ATP hydrolysis during pre-mRNA splicing. UAP56 protein is a vital splicing factor which is needed for connecting U2 small nuclear ribonucleoprotein with pre-mRNA, as well as takes a key part in mRNA export from the nucleus to the cytoplasm. Mutations in this protein may be connected to rheumatoid arthritis.

Ecotin inhibits pancreatic serine proteases. Ecotin protein inhibits chymotrypsin, trypsin, elastases, factor X, kallikrein as well as a variety of other proteases. The power of inhibition is not linked to a specific protease specificity.

Aspartoacylase is a homodimer which catalyzes the deacetylation of N-acetylaspartic acid (NAA) (a protein whose hydrolysis is crucial to maintenance of intact white matter) to generate acetate and L-aspartate. Aspartoacylase (ASPA) is expressed in the liver, lung and kidney tissue, as well as in the skeletal muscle and in cerebral white matter. NAA is ample in the brain where hydrolysis by aspartoacylase is believed to aid maintain white matter. In other tissues ASPA functions as a scavenger of NAA from body fluids. ASPA gene mutations cause Canavan disease (CAND or spongy degeneration of the brain).

Aspartoacylas or ASPA, is a protein, found in several tissues such as skeletal muscle, cerebral white matter, kidney, liver & lungs. ASPA is a homodimer that catalyses the deacetylation of Nacetylaspartic acid. In order to create L-aspartate & acetate.

NIT2 is a member of the nitrilase superfamily. NIT2 protein has an omega-amidase activity which removes potentially toxic intermediates by converting alpha-ketoglutaramate and alpha-ketosuccinamate to biologically useful alpha-ketoglutarate and oxaloacetate, respectively. In addition, Nit2 is widely distributed in nature and is thought to be a tumor suppressor protein.

Sialidase 1 (NEU1) is a lysosomal enzyme which cleaves terminal sialic acid residues from substrates such as glycoproteins and glycolipids. In the lysosome, the NEU1 enzyme is part of a heterotrimeric complex in cooperation with beta-galactosidase and cathepsin A. NEU1 gene mutations may lead to sialidosis, a lysosomal storage disease that can be the type 1 (cherry red -myoclonus syndrome or normosomatic type), which is late-onset, or the type 2 (the dysmorphic type), which takes place at an earlier age with increased acuteness.

Hyaluronidase-1 or HYAL1 is a protein, part of the endolytic glycoside hydrolase proteins group. Human hyaluronidases proteins, are 5 endo­β­N­acetyl­hexosaminidases (including HYAL1, HYAL2, HYAL3). Hyaluronidase-1 causes degradation to hyaluronic acid in the extracellular matrix of somatic tissues. HYAL1 needs an acidic environment and is the most common hyaluronidase in the plasma. Mutations in this protein can lead to mucopolysaccharidosis type IX and hyaluronidase deficiency.

HtrA2 also called Omi is a mammalian serine protease at high temperatures and has a chaperone activity at low temperature. The full-length HtrA2 is synthesized as a precursor protein and then targeted to the mitochondria where it is matured by the removal of N-terminal 133 residues. Mature HtrA2 consists of a putative transmembrane domain; an inhibitor of apoptosis protein (IAP)-binding motif; a single C-terminal PDZ domain that mediates protein-protein interactions. Recently, HtrA2 has known to contribute both to caspase-dependent and caspase-independent cell death.

DTD2 is e member of the DTD family. DTD2 protein hydrolyzes D-tyrosyl-tRNA(Tyr) into D-tyrosine and free tRNA(Tyr) as a defense mechanism against a harmful effect of D-tyrosine.

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.

ARG2 participates in the regulation of extra-urea cycle arginine metabolism and also in down-regulation of nitric oxide synthesis. Extrahepatic arginase functions to regulate L-arginine bioavailability to NO synthase. Since NO synthase is found in the penile corpus cavernosum smooth muscle, the clitoral corpus cavernosum and the vagina, ARG2 takes part in both male and female sexual arousal and therefore a potential target for the treatment of male and female sexual arousal disorders.