Search results

Hexokinases phosphorylate glucose to produce glucose-6-phosphate, thus committing glucose to the glycolytic pathway. HK3 encodes hexokinase 3. Similar to hexokinases 1 and 2, this allosteric enzyme is inhibited by its product glucose-6-phosphate. Hexokinase3 lacks the hydrophobic N-terminal sequence critical for targeting to mitochondria. Hexpkinase3 may have anabolic functions, providing H6P for glycogen or lipid synthesis.

P4HB is a multifunctional and highly abundant enzyme that is part of the protein disulfide isomerase family. When present as a tetramer consisting of two alpha and two beta subunits, P4HB has a role in hydroxylation of prolyl residues in preprocollagen. P4HB is a disulfide isomerase containing two thioredoxin domains that catalyze the formation, breakage and rearrangement of disulfide bonds.

LPL is a lipoprotein lipase, which is expressed in the heart, muscle, and adipose tissue. LPL acts as a homodimer, and has the dual functions of triglyceride hydrolase and ligand/bridging factor for receptor-mediated lipoprotein uptake. Type I hyperlipoproteinemia is a result of severe mutations which cause LPL deficiency, whereas less extreme mutations in LPL are linked to many disorders of lipoprotein metabolism. Lipoprotein lipase (LPL) is a fundamental enzyme in plasma triglyceride hydrolysis and is secreted by macrophages in the subendothelial space. LPL also promotes the development of atherosclerosis through facilitation of monocyte adhesion to endothelial cells, stimulation of tumor necrosis factor alpha (TNF) secretion and induction of vascular smooth muscle cell proliferation.

Uridine phosphorylase from Salmonella typhimurium (StUP) catalyzes the reversible phosphorolysis of uridine with the formation of ribose-1-phosphate and uracil.

Hydroxymethylglutaryl-CoA lyase (HMGCL) is a mitochondrial matrix protein which is a member of the HMG-CoA lyase family. HMGCL is a homodimer and participates in leucine catabolism and ketogenesis, the hepatic synthesis of ketone bodies which, during fasting, provides a major source of energy for the heart, brain and kidney. More precisely, HMGCL catalyzes the final step of these processes, the cleavage of 3-hydroxy-3-methylglutaryl-CoA to acetoacetic acid and acetyl-CoA.

PLA2G7 is a secreted enzyme which catalyzes the degradation of platelet-activating factor to biologically inactive products. The PLA2G7 enzyme is produced by inflammatory cells and hydrolyzes oxidised phospholipids in LDL. In the blood, PLA2G7 goes mainly with LDL and less than 20% is coupled with HDL.
PLA2G7 is implicated in the development of atherosclerosis and is also a marker for cardiac disease. PLA2G7 might have a major physiologic effect in the presence of inflammatory bodily responses.
PLA2G7 alters the action of PAF (platelet-activating factor) by hydrolyzing the sn-2 ester bond to yield the biologically inactive lyso-PAF. PLA2G7 has specificity for substrates with a short residue at the sn-2 position. PLA2G7 is inactive against long-chain phospholipids.
PLA2G7 gene defects are the source of platelet-activating factor acetylhydrolase deficiency, which is a trait that is present in 27% of the Japanese population.

PAPSS1 is a bifunctional enzyme with APS kinase and ATP sulfurylase activity. PAPSS1 facilitates two stages in the sulfate activation pathway, yielding 3'-phosphoadenylylsulfate (PAPS). Additionally, PAPSS1 takes part in the biosynthesis of sulfated L-selectin ligands in endothelial cells.

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.

Aspartoacylase 3 (ACY3) belongs to the Aspartoacylase subfamily. ACY3 has a vital role in deacetylating mercapturic acids in kidney proximal tubules. Aspartoacylase 3 localizes to the cytoplasm of S2 and S3 proximal tubules and also to the apical domain of S1 proximal tubules. In addition, ACY3 protein is expressed at low levels in the stomach, testis, heart, brain, lung and liver, and can function as an HCV (Hepatitis C virus) core binding protein.

Cathepsin-Z (CTSZ) is a lysosomal cysteine proteinase and a member of the peptidase C1 family. CTSZ, which is known also as cathepsin X and cathepsin P, exhibits carboxy-monopeptidase and carboxy-dipeptidase activities. CTSZ is expressed ubiquitously in cancer cell lines and primary tumors and as other members of this family, takes part in tumorigenesis.

The enzyme Arylsulfatase A, also known as cerebroside-sulfatase, is responsible to break down sulfatides. The main molecule that Arylsulfatase A breaks down is cerebroside 3-sulfate into cerebroside and sulfate. The enzyme is encoded by the ARSA gene in humans. Phosphate can form a covalent bond with the Arylsulfatase A’s active site 3-oxoalanine, thus, inhibits the protein.

OGG1 is a DNA glycosylase enzyme which takes part in base excision repair. OGG1 protein is the main enzyme accountable for the excision of 7,8-dihydro-8-oxoguanine (8-oxoG), a mutagenic base byproduct which arises as a result of exposure to reactive oxygen species (ROS). OGG1 shows beta lyase activity that nicks DNA 3 to the lesion.

Pyridoxine-5'-phosphate oxidase (PNPO) is the rate-limiting enzyme in vitamin B6 synthesis. Vitamin B6 (Pyridoxal 5-prime-phosphate or PLP) is vital for normal cellular function, and some cancer cells have notable differences in vitamin B6 metabolism compared to their normal counterparts.Vitamin B6 is an essential co-factor for enzymes involved in both homocysteine metabolism and synthesis of neurotransmitters such as catecholamine. Mutations in the PNPO gene result in PNPO deficiency, a form of neonatal epileptic encephalopathy.

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.

Cathepsin-A (CTSA) is a protective protein which is crucial for both the activity of beta-galactosidase and neuraminidase, CTSA associates with these enzymes and exerts a protective function required for their stability and activity. The CTSA protein is also a carboxypeptidase and can deamidate tachykinins. CTSA is a component of the lysosomal multienzyme complex along with beta-galactosidase and sialidase Neu1. CTSA is a multicatalytic enzyme with deamidase and esterase in addition to carboxypeptidase activities.

EXO2 is a 3'-to-5' exonuclease specific for small (primarily 5 nucleotides or less in length) single-stranded RNA and DNA oligomers. RNA Exonuclease 2 (REXO2) takes part in DNA repair, replication, and recombination, and in RNA processing and degradation. EXO2 is involved in resistance of human cells to UV-C-induced cell death via its part in the DNA repair process.

HEXA is the alpha subunit of the lysosomal enzyme beta-hexosaminidase which, combined with the cofactor GM2 activator protein, catalyzes the degradation of the ganglioside GM2, and other molecules having N-acetyl hexosamines terminus. The two subunits composing Beta-hexosaminidase, alpha and beta, belong to the glycosyl hydrolases family and are encoded by distinct genes. Alpha subunit gene mutations can cause Tay-Sachs disease (GM2-gangliosidosis type I).

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.

Dsb proteins (DsbA, DsbB, DsbC, and DsbD) catalyze formation and isomerization of protein disulfide bonds in the periplasm of Escherichia coli. DsbC is periplasmic enzyme known as a disulfide isomerase and can convert aberrant disulfide bonds to correct ones.

3-ketodihydrosphingosine reductase (KDSR) is a 332 amino acid multi-pass membrane protein which localizes to the ER and is a member of the short-chain dehydrogenases/reductases (SDR) family. KDSR is a secreted protein that is weakly expressed in hematopoietic tissue. Furthermore, KDSR catalyzes the reduction of 3-ketodihydrosphingosine (KDS) to dihydrosphingosine (DHS). The putative active site residues of KDSR are found on the cytosolic side of the endoplasmic reticulum membrane. Chromosomal rearrangement in the KDSR gene is a cause of follicular lymphoma, aka type II chronic lymphatic leukemia.

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.

Human Ubquitin Conjugating Enzyme 9 (Ubc9) is a member of the E2 family and is specific for the conjugation of SUMO to a variety of target proteins. SUMO conjugation to target proteins is mediated by a different, but analogous, pathway to ubiquitinylation. This E2 is unusual in that it interacts directly with protein substrates that are modified by sumolyation, and may play a role in substrate recognition. Ubc9 can mediate the conjugation of SUMO-1 to a variety of proteins including RanGAP1, I?B?, and PML without the requirement of an E3 ligase.