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Hemopexin (or haemopexin) is a plasma protein that binds heme with the highest affinity of any known protein. Hemopexin is generally expressed in liver, and belongs to acute phase reactants, the synthesis of which is induced after inflammation. Heme is potentially very toxic because of its ability to intercalate into lipid membrane and to generate hydroxyl radicals. Hemopexin’s function of scavenging the heme released or lost by the turnover of heme proteins such as hemoglobin defends the body from the oxidative damage that free heme can cause. Additionally, hemopexin discharges its bound ligand for internalisation upon interacting with a specific receptor located on the surface of liver cells. This hemopexin function is in order to preserve the body's iron. Hemopexin’s levels in the serum are an indication of how much heme is present in the blood. Low Hemopexin levels show that there is a lot of it in the serum. For that reason, low hemopexin levels indicate that there has been consid

HNMT is located in the cytosol and uses S-adenosyl-L-methionine as the methyl donor. In the mammal’s brain,N(tau)-methylation controls the neurotransmitter activity of histamine since diamine oxidase is not located in the central nervous system. A well known genetic polymorphism influences the activity levels of HNMT gene product in red blood cells. HNMT inactivates histamine by n-methylation. HNMT is involved in degrading histamine and in regulating the airway response to histamine. Histamine is involved in regulation and modulation of immune response through the stimulation of four distinct subtypes of receptors, H1, H2, H3, and H4, that present on the target cells. Histamine is inactivated by the histamine-metabolizing enzyme HNMT in bronchus, kidney, and the central nervous system.

TNFR2 belongs to the TNF-receptor superfamily. TNFR2 is receptor with high affinity for TNFSF2/TNF-alpha and approximately 5-fold lower affinity for homotrimeric TNFSF1/lymphotoxin-alpha. TNFR2 mediates the majority of the metabolic effects of TNF-alpha. In addition, knockout studies in mice propose a role for TNFR2 in protecting neurons from apoptosis by stimulating antioxidative pathways. TNFR2 expression might have a significant role in the angiogenesis, tumor cell proliferation and metastasis of Invasive micropapillary carcinoma of the breast.
There are 2 types of soluble TNF receptors: sTNFR-I and sTNFR-II, which act to neutralize the biological activities of TNF alpha and TNF beta. The levels of these soluble receptors seem to increase as a result of shedding of the extracellular domains of the membrane bound receptors. High levels of soluble TNF receptors are found in the amniotic fluid of pregnant women. TNFR2 and TNFR1 form a heterocomplex which mediates the recruitment of 2 anti-apoptotic proteins, c-IAP1 and c-IAP2, which possess E3 ubiquitin ligase activity. IAPs’ function in TNF-receptor signaling is unknown; nevertheless, c-IAP1 is believed to potentiate TNF-induced apoptosis by the ubiquitination and degradation of TNF-receptor-associated factor 2, which mediates anti-apoptotic signals. Oxidative stress promotes TNFR1 and TNFR2 self-interaction, ligand-independent and enhanced ligand-dependent TNF signaling. TNF-a, TNFR1 and TNFR2 have roles in cellular differentiation. TNFR1 and TNFR2 function in cell type-specific renal injury.

A fusion tag called FLAG consists of eight amino acids (AspTyrLysAspAspAspAspLys) including an enterokinase-cleavage site. FLAG is specifically designed for immunoaffinity chromatography. It allows elution under non-denaturing conditions. Several antibodies against this peptide have been developed. One antibody denoted as M1 binds the peptide in the presence of bivalent metal cations preferably Ca(+). Elution is effected by chelating agents. Another strategy is competitive elution with excess of free Flag Peptide.
The FLAG peptide purifies and detects recombinant fusion proteins. FLAG peptide is useful in Western blotting, immunocytochemistry, immunoprecipitation, flow cytometry, protein purification, and in the study of protein-protein interactions, cell ultrastructure, and protein localization. Flag peptide is a hydrophilic tag which significantly improves the detection and purification of recombinant fusion proteins.

Cytosolic and membrane-bound types of GST are encoded by 2 different supergene families. There are 8 classes of the soluble cytoplasmic mammalian GST: alpha, kappa, mu, omega, pi, sigma, theta and zeta. 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 arranged in a gene cluster on chromosome 1p13.3 and aare highly polymorphic. These genetic differences can change an individual's resistance to carcinogens and toxins as well as affect the toxicity and efficacy of certain drugs. Null mutations of this class mu gene have been linked with the rise in a number of cancers.

Pyruvate Dehydrogenase Complex, Component X, also known as PDHX, encodes the E3 binding protein subunit of the PDH complex which contains 3 catalytic subunits. PDHX tethers E3 dimers to the E2 core of the pyruvate dehydrogenase complexes of eukaryotes. This specific binding is critical for a functional PDH complex.

Endothelial cells express three different vascular endothelial growth factor (VEGF) receptors, belonging to the family of receptor tyrosine kinases (RTKs). They are named VEGFR-1 (Flt-1), VEGFR-2 (KDR/Flk-1), VEGFR-3 (Flt-4). Their expression is almost exclusively restricted to endothelial cells, but VEGFR-1 can also be found on monocytes, dendritic cells and on trophoblast cells. The flt-1 gene was first described in 1990. The receptor contains seven immunoglobulin-like extracellular domains, a single transmembrane region and an intracellular splited tyrosine kinase domain. Compared to VEGFR-2 the Flt-1 receptor has a higher affinity for VEGF but a weaker signaling activity. VEGFR-1 thus leads not to proliferation of endothelial cells, but mediates signals for differentiation. Interestingly a naturally occuring soluble variant of VEGFR-1 (sVEGFR-1) was found in HUVE supernatants in 1996, which is generated by alternative splicing of the flt-1 mRNA. The biological functions of sVEGFR-1 still are not clear, but it seems to be an endogenous regulator of angiogenesis, binding VEGF with the same affinity as the full-length receptor.

Galectin-4 is a member of the subfamily of galectins composed of two carbohydrate recognition domains having similar peptide chains. The galectins are a family of beta-galactoside-binding proteins having a role in modulating cell-cell and cell-matrix interactions, which inhibits chronic inflammations, GVHD, and allergic responses. LGALS4 expression is limited to small intestine, colon, and rectum, and it is underexpressed in colorectal cancer. LGALS4 binds as an endogenous ligand to glycosphingolipids having 3-O-sulfated Gal residues and bind as well to cholesterol-3-sulfate. LGALS4 takes part in cell adhesion. LGALS4 plays a role in crosslinking the lateral cell membranes of the surface-lining epithelial cells, thus supporting epithelial integrity against mechanical stress exerted by the bowel lume. LGALS4 is in charge of intestinal inflammation via selective regulation of peripheral and mucosal T-cell cell cycle, in addition to cell death by apoptosis of T-cells by a pathway independent of the activation of caspases. LGALS4 blockade decreases TNF-alpha inhibitor induced T-cell death. LGALS4 decreases pro-inflammatory cytokine secretion including IL-6 & IL-17.

The MCFD2-LMAN1 complex forms an explicit cargo receptor for the ER-to-Golgi transport of selected proteins. MCFD2 is involved in the secretion of coagulation factors. MCFD2 is expressed by neural stem/progenitor cells of the hippocampus, and localized to region where neurogenesis persists throughout life. MCFD2 prevents NSC cell death and maintains stem cell characteristics. MCFD2 forms a complex with LAMN1 that facilitates the transport of coagulation factors V and VIII from the endoplasmic reticulum to the Golgi apparatus through an endoplasmic reticulum Golgi intermediate compartment. Mutations in the MCFD2 cause Factor V and Factor VIII combined deficiency.

Transforming growth factor betas (TGF Betas) mediate many cell-cell interactions that occur during embryonic development. Three TGF Betas have been identified in mammals. TGF Beta 1, TGF Beta 2 and TGF Beta 3 are each synthesized as precursor proteins that are very similar in that each is cleaved to yield a 112 amino acid polypeptide that remains associated with the latent portion of the molecule.

HPRT1 has a main part in the generation of purine nucleotides through the purine salvage pathway. HPRT1 primarily functions to salvage purines from degraded DNA to renewed purine synthesis. Therefore, it performs as a catalyst in the reaction between guanine and phosphoribosyl pyrophosphate to form GMP.

Ciliary Neurotrophic Factor Receptor (CNTFR) is a member of the type I cytokine receptor family and binds to CNTF. The alpha subunit provides the receptor specificity. Sole nucleotide polymorphisms in CNTFR has been associated with variations in muscle strength, in addition to early onset of eating disorders.

Complement Factor D (Adipsin), which belongs to the trypsin family of peptidases, is involved in the alternative complement pathway of the complement system where it cleaves factor B. In the alternative complement pathway, Adipsin is best known for its role in humoral suppression of infectious agents. In addition, Adipsin is a serine protease which is secreted by adipocytes into the bloodstream. Ultimately, Adipsin has a high level of expression in fat, proposing a role for adipose tissue in immune system biology.

Histidine triad nucleotide-binding protein 2 (HINT2) belongs to the triad proteins, which are nucleotide hydrolases and transferases that act on the alpha-phosphate of ribonucleotides. Hydrolase is most likely involved in steroid biosynthesis, furthermore it might play a role in apoptosis. HINT2 shows high expression in liver and pancreas. Expression is significantly down-regulated in hepatocellular carcinoma (HCC) patients.

SCG3 belongs to the chromogranin/secretogranin family of neuroendocrine secretory proteins. Though, the function of SCG3 is unknown, Granins operate as precursors for biologically active peptides. Several granins are known to serve as helper proteins in sorting and proteolytic processing of prohormones.

ADP-ribosylation factor 3 (ARF3) belongs to the human ARF gene family. This family encodes small guanine nucleotide-binding proteins which stimulate the ADP-ribosyltransferase activity of cholera toxin and have a role in vesicular trafficking and as activators of phospholipase D. ARF3 functions as an allosteric activator of the cholera toxin catalytic subunit, an ADP-ribosyltransferase. ARF3 is involved in protein trafficking; may modulate vesicle budding and uncoating within the Golgi apparatus. The ARF3 gene is comprised of 5 exons and 4 introns.

ASF1 Anti-Silencing Function 1 Homolog B (ASF1B) belongs to the H3/H4 family of histone chaperone proteins and is similar to the anti-silencing function-1 protein in yeast. ASF1B is the substrate of the tousled-like kinase family of cell cycle-regulated kinases, and may have a crucial role in modulating the nucleosome structure of chromatin by guaranteeing a regular supply of histones at sites of nucleosome assembly. ASF1B cooperates with CAF-1 (chromatin assembly factor 1) to stimulate replication-dependent chromatin assembly. ASF1B is highly expressed in the testis and at lower levels in colon, small intestine and thymus. ASF1B is necessary for spermatogenesis.

Eukaryotic Translation Elongation Factor 1 Gamma (EEF1G) takes part in anchoring the complex to additional cellular components. EEF1G is a multi-protein complex which is in charge of the delivery of aminoacyl-tRNAs to the ribosome. Over expression of EEF1G is linked with pancreatic cancer, due to the role of EEF1G protein in the oncogenic transformation process.

EFNA1 belongs to the ephrin (EPH) family. The EPH subfamily is the biggest group of receptor protein kinases and they take part in vital nervous system function and development.

Beta-1,3-glucuronyltransferase 3 (B3GAT3) is involved in forming the linkage tetrasaccharide present in heparan sulfate and chondroitin sulfate. B3GAT3 has a part in the biosynthesis of l2/HNK-1 carbohydrate epitope on glycoproteins. B3GAT3 shows strict specificity for Gal-beta-1,3-Gal-beta-1,4-Xyl, exhibiting negligible incorporation into other galactoside substrates including Galbeta1-3Gal beta1-O-benzyl, Galbeta1-4GlcNAc and Galbeta1-4Glc.

Core 1 Beta3-Gal-T1 also known as,C1GALT1 creates the common core 1 O-glycan structure, Gal-beta-1-3GalNAc-R, by the transfer of Gal from UDP-Gal to GalNAc-alpha-1-R. Core 1 is a precursor for lots of extended mucin-type O-glycans on cell surface and secreted glycoproteins. Studies in mice have shown that this gene takes a main role in angiogenesis, thrombopoiesis and kidney homeostasis.