Search results

Uridine 5'-monophosphate synthase (UMPS), is a bifunctional enzyme that catalyzes the ultimate two steps of the de novo pyrimidine biosynthetic pathway. UMPS in eukaryotes links the orotate phosphoribosyltransferase and the orotidine-5’-monophosphate (OMP) decarboxylase activities into a single protein. The harmony of these 2 enzymes is assumed to be stabilized the catalytic centers as a result of the low molar concentration of the protein in mammalian cells. Mutations in UMPS are the reason of inherited orotic aciduria disease.

PGAM1 is part of the phosphoglycerate mutase family. PGAM1 is an essential component of glucose and 2,3-BPGA (2,3-bisphosphoglycerate) metabolism and catalyzes the reversible reaction of 3-phosphoglycerate (3-PGA) to 2-phosphoglycerate (2-PGA) in the glycolytic pathway. PGAM1 is a dimeric enzyme containing, in different tissues, different proportions of a slow-migrating muscle (MM) isozyme, a fast-migrating brain (BB) isozyme, and a hybrid form (MB). PGAM1 mutations lead to muscle phosphoglycerate mutase deficiency, a.k.a. glycogen storage disease X.

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.

Maltose Binding Protein is a member of the maltose/maltodextrin system of E.Coli, which is accountable for the uptake and efficient catabolism of maltodextrins. The maltose/maltodextrin is a complex regulatory and transport system involving many proteins and protein complexes.
MBP elevates the yield of its fusion partner in many cases and is often able to promote the solubility of polypeptides to which it is fused.

GPT catalyzes the reversible transamination between alanine and 2-oxoglutarate to create pyruvate and glutamate. GPT has a crucial part in the intermediary metabolism of glucose and amino acids. GPT is broadly used as an indicator of liver reliability or hepatocellular destruction in clinical tests.

Glutathione reductase (Gor) is a member of the class-I pyridine nucleotide disulfide oxidoreductase family. The main role of the Gor protein is to uphold high levels of reduced glutathione in the cytosol. With the associated oxidation of NADPH, Gor transforms oxidized glutathione to the reduced form. The active site of the Gor protein is a redox-active disulfide bond.

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.

Uromodulin is the most abundant protein in normal urine. Its secretion in urine follows proteolytic cleavage of the ectodomain of its glycosyl phosphatidylinosital-anchored counterpart that is situated on the luminal cell surface of the loop of Henle. Uromodulin plays a role as a constitutive inhibitor of calcium crystallization in renal fluids. Secretion of uromodulin in urine provides protection against urinary tract infections caused by uropathogenic bacteria. Defects in Uromodulin expression are associated with the autosomal dominant renal disorders medullary cystic kidney disease-2 (MCKD2) and familial juvenile hyperuricemic nephropathy (FJHN). These disorders are characterized by juvenile onset of hyperuricemia, gout, and progressive renal failure. While several transcript variants may exist for this gene, the full-length natures of only two have been described to date. UMOD is involved in regulating the circulating activity of cytokines as it binds to il-1, il-2 and tnf with high affinity.

Malate dehydrogenase (EC1.1.1.37) is an enzyme in the citric acid cycle that catalyzes the conversion of malate into oxaloacetate (using NAD+) and vice versa (this is a reversible reaction). Malate dehydrogenase is not to be confused with malic enzyme, which catalyzes the conversion of pyruvate using NADPH.
Malate dehydrogenase is also involved in gluconeogenesis, the synthesis of glucose from smaller molecules. Pyruvate in the mitochondria is acted upon by pyruvate carboxylase to form oxaloacetate, a citric acid cycle intermediate. In order to get the oxaloacetate out of the mitochondria, malate dehydrogenase reduces it to malate, and it then traverses the inner mitochondrial membrane. Once in the cytosol, the malate is oxidized back to oxaloacetate by cytosolic malate dehydrogenase. Finally, phosphoenol-pyruvate carboxy kinase (PEPCK) converts oxaloacetate to phosphoenol pyruvate.

Proprotein Convertase Subtilisin/Kexin Type 1 Inhibitor (PCSK1N) takes part in the control of the neuroendocrine secretory pathway. PCSK1N inhibits prohormone convertase 1, which regulates the proteolytic cleavage of neuroendocrine peptide precursors. PCSK1Nslows down convertase-mediated processing of proopiomelanocortin and proenkephalin and also monitors the intracellular timing of PCSK1.

Epiregulin is part of the EGF family. Epiregulin functions as a ligand of EGFR, as well as a ligand of most members of the ERBB (v-erb-b2 oncogene homolog) family of tyrosine-kinase receptors.Epiregulin is expressed mostly in the placenta and peripheral blood leukocytes and in specific carcinomas of the bladder, lung, kidney and colon. Epiregulin stimulates the proliferation of keratinocytes, hepatocytes, fibroblasts and vascular smooth muscle cells. Epiregulin inhibits the growth of several tumor-derived epithelial cell lines. Human Epiregulin is initially synthesized as a glycosylated 19.0 kDa transmembrane precursor protein, which is processed by proteolytic cleavage to produce a 6.0 kDa mature secreted sequence.

Aminoacylase-1 is a cytosolic, homodimeric, zinc-binding enzyme that catalyzes the hydrolysis of acylated L-amino acids to L-amino acids and acyl group, and has been postulated to function in the catabolism and salvage of acylated amino acids. ACY1 has been assigned to chromosome 3p21.1, a region reduced to homozygosity in small-cell lung cancer (SCLC), and its expression has been reported to be reduced or undetectable in SCLC cell lines and tumors. The amino acid sequence of human aminoacylase-1 is highly homologous to the porcine counterpart, and ACY1 is the first member of a new family of zinc-binding enzymes.

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.

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.

Listeriolysin O (aka LLO) is a hemolysin produced by Listeria monocytogenes bacteria, the pathogen responsible for causing listeriosis. The toxin may be regarded as a virulence factor, since it is crucial for the virulence of L. monocytogenes. LLO is a single polypeptide protein encoded by the hlyA gene and composed of 529 residues. LLO is a thiol-activated cholesterol-dependent pore forming toxin protein; therefore, it is activated by reducing agents and inhibited by oxidizing agents. Still, LLO differs from other thiol-activated toxins, as its cytolytic activity is maximized at a pH of 5.5. Inside the acidic phagosomes (average pH ~ 5.9) of cells that have phagocytosed L. monocytogenes, LLO is selectively activated by maximizing activity at a pH of 5.5. Following the phagosome lysis by LLO, the bacterium breaks out into the cytosol, where it is able to grow intracellularly, and the toxin has reduced activity in the more basic cytosol. Thus, LLO permits L. monocytogenes to break out from the phagosomes into the cytosol without harming the plasma membrane of the infected cell, which allows the bacteria to live intracellularly, where they are sheltered from extracellular immune system factors such as the complement system and antibodies. LLO also brings about dephosphorylation of histone H3 and deacetylation of histone H4 in the early phases of infection, before entry of L. monocytogenes into the host cell. The pore-forming activity is not implicated in causing the histone modifications. The modifications of the histones affect the down regulation of genes encoding proteins involved in the inflammatory response. Therefore, LLO may be significant in subverting the host immune response to L. monocytogenes. At its NH2-terminus it possesses a 25 residues long typical signal sequence excited during the secretion process. Moreover, in its NH2-terminus there is also a 19 amino acids PEST- like sequence that may target this toxin for degradation. The PEST-like sequence found in LLO and is considered crucial for virulence, given that mutants lacking the sequence lysed the host cell. Nevertheless, contrary to PEST's supposed role in protein degradation, evidence implies that the PEST-like sequence may control LLO production in the cytosol rather than increase degradation of LLO.

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.

ALDOB is a tetrameric glycolytic enzyme which catalyzes the reversible cleavage of fructose 1-phosphate into dihydroxyacetone phosphate and glyceraldehyde. Fructose-bisphosphate aldolase B (ALDOB) is one of 3 known aldolase isoenzymes, and is located in the kidney and the small adult intestine where it is linked with aldolases A or C. ALDOB is regulated by Insulin and glucagon and is implicated in hereditary fructose intolerance disease.

Seed storage proteins have been identified as major allergens in several other tree nuts and peanut. 2S albumin Cor a 14.0101 is a seed storage protein in hazelnut. Sensitization to Cor a 14.0101 may cause a severe allergic reaction, mainly in children.

Ornithine Aminotransferase is a mitochondrial enzyme which is an important factor that converts arginine and ornithine into the major excitatory and inhibitory neurotransmitters glutamate and GABA. Ornithine Aminotransferase mutations result in a deficiency that cause the autosomal recessive eye disease Gyrate Atrophy.

Kallikrein-3 (KLK3) is a part of the kallikrein-related peptidase family. Kallikreins are a subgroup of serine proteases having various physiological functions. Numerous kallikreins take part in carcinogenesis and some may be prospective cancer and other disease biomarkers. Kallikrein-3 is 1 of the 15 kallikrein subfamily members located in a cluster on chromosome 19 and is a protease present in seminal plasma. KLK3 hydrolyzes semenogelin-1 consequently leading to the liquefaction of the seminal coagulum. KLK3 acts normally in the liquefaction of seminal coagulum, probably by hydrolysis of the high molecular mass seminal vesicle protein. Serum level of the KLK3 protein, called PSA in the clinical setting, is beneficial in the diagnosis and monitoring of prostatic carcinoma.

Thiamin pyrophosphokinase 1 (TPK1) is a homodimer which catalyzes the phosphorylation of thiamine to thiamine pyrophosphate. TPK1 is found in the heart, kidney, testis, small intestine and peripheral blood leukocytes, and at very low levels in a variety of tissues. TPK1 gene defects cause the thiamine metabolism dysfunction syndrome type 5, episodic encephalopathy type (THMD5), which is an autosomal recessive metabolic disorder due to an inborn error of thiamine metabolism.

CK-MB Type II possesses the naturally occurring carboxy-terminal amino acid lysine.
This occurs during a myocardial infarct (MI or heart attack) when CK-MB Type II is released from damaged heart muscle, and the C-terminal lysine is cleaved in the blood stream, thus creating CK-MB Type I. This difference can be exploited in diagnosis of an MI.

TIMP2 belongs to the TIMP gene family. The proteins encoded by this gene family are natural inhibitors of the matrix metalloproteinases, a group of peptidases that take part in degradation of the extracellular matrix. Besides having an inhibitory role against metalloproteinases, the encoded protein has a exclusive part among TIMPfamily members in its capability to directly suppress the proliferation of endothelial cells. Consequently, the encoded protein is crucial to the conservation of tissue homeostasis by suppressing the production of quiescent tissues as an answer to angiogenic factors, and by inhibiting protease activity in tissues undergoing renovation of the extracellular matrix.

This E2 enzyme encodes for the human homolog of the yeast DNA repair gene RAD6, which is induced by DNA damaging agents. UBE2B can conjugate ubiquitin to histone H2A in an E3- independent manner in vitro, and is essential for the multi-ubiquitination and degradation of N-end rule substrates. Additionally, UBE2B may have a role in sepsis-induced muscle protein proteolysis and cancer-induced cachexia.