Search results

GST family of enzymescomprises a long list of cytosolic, mitochondrial, and microsomalproteinsthat are 45-55 kDa (dimer form) size and are capable of multiple reactions with a multitude of substrates, both endogenousand xenobiotic. GST catalyses the conjugation of reduced glutathione meaning the sulfhydryl group, to electrophilic centers on a wide variety of substrates. This activity is useful in the detoxification of endogenous compounds such as peroxidised lipids, as well as the metabolism of xenobiotics. GST binds toxins and function as transport protein. Glutathione S-transferase is used to create the so-called 'GST gene fusion system'. The GST is used to purify and detect proteins of interest. In a GST gene fusion system, the GST sequence is incorporated into an expression vector alongside the gene sequence encoding the protein of interest. Induction of protein expression from the vector's multiple cloning sites results in expression of a fusion protein - the protein of interest fused to the GST protein. This GST-fusion protein can then be purified from cells via its high affinity for glutathione. Fusion proteins offer an important biological assay for direct protein-to-protein interactions. The GST tag has the size of 220 amino acids, which, compared to other tags like the myc- or the FLAG-tag, is quite big. It is fused to the N-terminusof a protein. However, many commercially-available sources of GST-tagged plasmids include a thrombindomain for cleavage of the GST tag during protein purification. A GST-tag is often used to separate and purify proteins that contain the GST-fusion. GST-fusion proteins can be produced in Escherichia coli, as recombinant proteins.

ANXA1 is part of the family of Ca(2+)-dependent phospholipid binding proteins which have a Mw between 35kDa-40kDa and are situated on the cytosolic face of the plasma membrane. ANXA1 protein has a Mw of 40kDa, with phospholipase A2 inhibitory activity to bind from two to four calcium ions with high affinity. Since phospholipase A2 is necessary for the biosynthesis of the potent mediators of inflammation, prostaglandins and leukotrienes, ANXA1 might have potential anti-inflammatory activity. ANXA1 promotes membrane fusion and iplays a role in exocytosis. The recognition of ANXA1 protein by immunocytochemical leads a simple, highly sensitive and specific assay for diagnosis of hairy cell leukemia.

2-Enoyl-Coenzyme A (CoA) Hydratase, Beta (HADHB) is the beta subunit of the mitochondrial trifunctional protein, that catalyzes the last 3 phases of mitochondrial beta-oxidation of long chain fatty acids. HADHB binds RNA and reduces the stability of various mRNAs. Mutations in HADHB cause trifunctional protein deficiency.

Synaptotagmin-11 (SYT11) protein may be involved in Ca2+-dependent exocytosis of secretory vesicles through Ca2+ and phospholipid binding to the C2 domain or may function as Ca2+ sensors in the process of vesicular trafficking and exocytosis.

Methionine sulfoxide reductase B3 (MSRB3) is a member of the methionine sulfoxide reductases (MSR) family proteins. MSRB3 catalyzes the reduction of methionine sulfoxide to methionine. The MSRB3 enzyme acts as a monomer and requires zinc as a cofactor. MSRs are thought to defend against reactive oxygen species-induced oxidative damage in various organs, including the most environmentally exposed organ, the human skin. MSRB3 has a vital role in cold tolerance by eliminating MetO and ROS which accumulate at the ER during cold acclimation.

OTOR proteins is also known as fibrocyte-derived protein (Fdp) and Melanoma inhibitory activity-like (MIAL). Otoraplin is a member of the melanoma-inhibiting activity gene family. Otoraplin is a secreted 16 kDa globular protein that is expressed in the inner ear by periotic mesenchyme and developing and mature fibrocytes. OTOR is highly homologous to MIA/cartilage-derived retinoic acid-sensitive protein (CD-RAP), which is a cartilage-specific protein that is also expressed in malignant melanoma cells. The 111 amino acid mature human otoraplin contains 1 SH3 domain (46 – 107 amino acids) and a Tyr at position 50 that is reportedly sulfated. Otoraplin takes pasrt in the initiation of periotic mesenchyme chondrogenesis.
Otoraplin is secreted through the Golgi apparatus and plays a role in cartilage development and maintenance. A frequent polymorphism in the translation start codon of OTOR can abolish translation and may be associated with forms of deafness.

Thymidine kinase 2 mitochondrial (TK2) is a member of the DCK/DGK family. TK2 is an enzyme, a phosphotransferase (a kinase): 2'-deoxythymidine kinase, ATP-thymidine 5'-phosphotransferase. Thymidine kinase is found in most living cells. Thymidine kinase is present in 2 forms in mammalian cells, TK1 and TK2. Thymidine kinases have a central function in the synthesis of DNA and thus in cell division, since they are part of the exceptional reaction chain to introduce deoxythymidine into the DNA. TK2 is a deoxyribonucleoside kinase which specifically phosphorylates thymidine, deoxycytidine, and deoxyuridine. TK2 localizes to the mitochondria and is essential for mitochondrial DNA synthesis. TK2 gene defects are a cause of mitochondrial DNA depletion syndrome type 2 (MTDPS2).

Glycinin Ara h 3 is a seed storage protein, 11 S globulin and trypsin inhibitor from peanut. Each subunit of the hexamer is composed of an acidic and a basic chain derived from a single precursor and linked by a disulfide bond. Ara h 3 and Ara h 4 are isoforms. Glycinin is the source of sulfur-containing amino acids in seed meals and it exists in the seeds of many leguminous and non-leguminous plants.

Indoleamine 2,3-Dioxygenase 1 (IDO1) catalyzes the primary and rate-limiting stage in tryptophan catabolism to N-formyl-kynurenine. IDO1 affects on various tryptophan substrates including D-tryptophan, and serotonin and is expressed in dendritic cells, monocytes, and macrophages. IDO1 takes part in a range of pathophysiological processes like neuropathology, antimicrobial and antitumor defense, immunoregulation, and antioxidant activity. IDO1 regulates T-cell behavior by its pericellular catabolization of the necessary amino acid tryptophan.

Eotaxin-2, also called MPIF2 & Ckb6, is a novel CC chemokine produced by activated monocytes and T lymphocytes. Eotaxin-2 selectively chemoattracts cells expressing CCR3 including eosinophils, basophils, Th2 T cells, mast cells, and certain subsets of dendritic cells. Furthermore, Eotaxin-2 inhibits the proliferation of multipotential hematopoietic progenitor cells. The mature protein, which includes C-terminal truncation, contains 78 amino acids (92 amino acids for the mouse homolog, without C-terminal truncation).
CCL24 functions as a chemotactic chemokine for resting t-lymphocytes, and eosinophils. CCL24 has lower chemotactic activity for neutrophils but none for monocytes and activated lymphocytes. CCL24 is a strong suppressor of colony formation by a multipotential hematopoietic progenitor cell line and binds to CCR3.

O-Sialoglycoprotein Endopeptidase, also known as OSGEP is a member of the KAE1 / TsaD family. OSGEP is essential for the formation of threonylcarbamoyl group on adenosine at position 37 (t6A37) in tRNAs which read codons beginning with adenine. OSGEP take a direct catalytic part in the above reaction, however other proteins of the complex are required to fulfill this activity.

TSNAX is a member of translin family. TSNAX particularly interacts with translin, a DNA-binding protein that binds consensus sequences at breakpoint junctions of chromosomal translocations. TSNAX works in combination with TSN as an endonuclease involves in the activation of the RNA-induced silencing complex (RISC). TSNAX has bipartite nuclear targeting sequences that afford nuclear transport for translin, which lacks any nuclear targeting motifs.

TYRO3 Protein Tyrosine Kinase or TYRO3 is a transmembrane receptor tyrosine kinase. TYRO3 has crucial role in essential processes such as cell migration, actin reorganization and cell survival. It is activated and signaled by MAPK/ERK and PI3K/AKT that expedites the cellular functions of protein.

QDPR belongs to the short-chain dehydrogenases/reductase (SDR) family of enzymes. Operating as a homodimer, QDPR has an imperative role in the recycling of tetrahydrobiopterin (BH4), a vital cofactor for the hydroxylation of the aromatic amino acids (tryptophan, tyrosine and phenylalanine). More precisely, QDPR catalyzes the regeneration of BH4 from quinonoid dihydrobiopterin (qBH2), the product generated from the hydroxylation reactions. Mutations in the QDPR gene may lead to phenylketonuria II.

Rhodanese is a mitochondrial matrix enzyme that is encoded by the nucleus. Rhodanese is involved in cyanide detoxification, the formation of iron-sulfur proteins, and the modification of sulfur-containing enzymes. Rhodanese catalyzes the chemical reaction of thiosulfate & cyanide to sulfite & thiocyanate (detoxification). Rhodanese is part of the transferase family of proteins. Rhodanese includes two highly conservative domains, identified as rhodanese homology domains. In mammals, the majority of cyanide is converted to thiocyanate. Rhodanese has weak mercaptopyruvate sulfurtransferase activity.

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.

SNX1 belongs to the large family of hydrophilic proteins that interact with a range of receptor types that participate in intracellular trafficking. SNX1 and the associated splice variant, SNX1A, bind the EGFR, enable its transport to the lysosome, and thus contribute to the degradation of the receptor. SNX1 is related with cellular membranes, and they, also, associate with EGF, PDGF and the receptor tyrosine kinases.

Treponema pallidum is a gram-negative spirochaete bacterium and is considered to be metabolically crippled. There are at least four known subspecies: T. pallidum pallidum, T. pallidum pertenue, T. pallidum carateum and T. pallidum endemicum. The helical structure of T. pallidum pallidum allows it to move in a corkscrew motion through viscous mediums such as mucus. Treponema pallidum sub sp. pallidum has one of the smallest bacterial genomes at 1.14 million base pairs (Mb) and has limited metabolic capabilities, reflecting its adaptation through genome reduction to the rich environment of mammalian tissue.

Superoxide dismutase Mn (soda) belongs to the iron/manganese superoxide dismutase family. SodA destroys radicals that are typically produced within the cells and which are toxic to biological systems. SodA works by catalyzing the dismutation of the superoxide radical O2- to O2 and H2O2, which are then metabolized to H2O and O2 by catalase and glutathione peroxidase.

Chemokine (C-C motif) ligand 11 (CCL11) is a small cytokine belonging to the CC chemokine family that is also known as eotaxin. CCL11 selectively recruits eosinophils by inducing their chemotaxis, and therefore, is implicated in allergic responses. The effects of CCL11 are mediated by its binding to a G-protein-linked receptor known as a chemokine receptor. Chemokine receptors for which CCL11 is a ligand include CCR2, CCR3 and CCR5. The gene for human CCL11 (scya11) is encoded on three exons and is located on chromosome 17.

Streptavidin is a tetrameric protein secreted by Streptomyces avidinii which binds firmly to biotin. Streptavidin is widely used in molecular biology through its unique high affinity for the vitamin biotin. The dissociation constant (Kd) of the biotin-streptavidin complex is about ~10-15 mol/L. The strong affinity recognition of biotin and biotinylated molecules has made streptavidin one of the most important components in diagnostics and laboratory kits. The streptavidin/biotin system has one of the biggest free energies of association of yet observed for noncovalent binding of a protein and small ligand in aqueous solution (K_assoc = 10**14). The complexes are also extremely stable over a wide range of temperature and pH.

TPMT, thiopurine S-methyltransferase, is a cytosolic enzyme that metabolizes thiopurine drugs via S-adenosyl-L-methionine as the S-methyl donor and S-adenosyl-L-homocysteine as a byproduct. TPMT activity exhibits autosomal codominant genetic polymorphism, and patients inheriting TPMT-deficiency are at high risk of potentially fatal hematopoietic toxicity.

Cathepsin D is synthesized as a 54kDa precursor, which is proteolytically processed to an intermediate 48kDa single chain, which matures into more stable 34kDa and 14kDa two chain form. It is an estrogen-regulated lysosomal protease that has been suggested to facilitate cancer cell migration and invasion by digesting the basement membrane, extracellular matrix, and xonnective tissue. Because of its mitogenic and proteolytic activities, it has been implicated as a prognostic marker in many tumor types. Cathepsin D is expressed in epithelial cells as well as in macrophages.

Frataxin is a mitochondrial iron binding protein that is part of the FRATAXIN family. Frataxin functions in regulating mitochondrial iron transport and respiration. The expansion of intronic trinucleotide repeat GAA results in Friedreich ataxia. Frataxin plays a role in iron homeostasis. Frataxin is an anti-apoptotic protein which prevents mitochondrial damage and reactive oxygen species (ROS) production.