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Actin is an abundant cytoskeletal protein found in all mammalian cells. Six distinct actin isotypes have been identified in mammalian cells. Each is encoded by a separated gene and is expressed in a developmentally regulated and tissue-specific manner. α and β-cytoplasmic actins are expressed in a wide variety of cells. Whereas, expression of α-skeletal, α-cardiac, α-vascular and γ-enteric actins
are more restricted to specialized muscle cell type. Actin's filaments form part of the cytoskeleton and play essential roles in regulating cell shape and movement.

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SHP1 and SHP2 represent a subfamily of non-transmembrane protein-tyrosine phosphatases (PTPs) that contain two tandem SH2 (src homology 2) domains. SHPs have two N-terminal SH2 domains (N-SH2 and C-SH2), a classic PTP domain and a C-terminal tail harboring two tyrosyl phosphorylation sites which are phosphorylated differentially by receptor and non-receptor protein-tyrosine kinases (PTKs).
Whereas SHP2 is expressed ubiquitously, SHP1 is primarily expressed in hematopoietic cells and behaves as a key regulator controlling intracellular phosphotyrosine levels in lymphocytes.
SH2 domains (particularly the N-SH2) also regulate PTP activity. Basal SHP activity is low, but addition of a phosphotyrosyl peptide that binds the N-SH2 (Tyr–P peptide ligand) markedly stimulates catalysis.
SHP1 is implicated in signaling from receptor tyrosine kinases (RTKs), cytokine receptors, chemokine receptors and integrins. SHP1-deficient bone marrow macrophages are hyper-adherent to β1- and β2-integrin ligands.
Decreased SHP1 level causes abnormal T-lymphocyte proliferation and induces various types of leukemias. Introduction of the SHP1 gene back into a leukemia cell line and a prostate cancer cell line demonstrated the tumor suppressor function of SHP1.

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Glutathione peroxidases (Gpxs) are ubiquitously expressed proteins which catalyze the reduction of hydrogen peroxides and organic hydroperoxides by glutathione. There are several isoforms which differ in their primary structure and localization. The classical cytosolic /mitochondrial GPx1 (cGPx) is a selenium-dependent enzyme, first of the GPx family to be discovered. GPx2, also known as gastrointestinal GPx (GI-GPx), is an intracellular enzyme expressed only at the epithelium of the gastrointestinal tract (1). Extracellular plasma GPx (pGPx or GPx3) is mainly expressed by the kidney from where it is released into the blood circulation (2). Phospholipid hydroperoxide GPx4 (PH-GPx) expressed in most tissues, can reduce many hydroperoxides including hydroperoxides integrated in membranes, hydroperoxy lipids in low density lipoprotein or thymine (3). All mammalian GPx family members, except for the recently described Cys containing GPx3 and epididymis-specific secretory GPx (eGPx or GPx5) isoforms, possess selenocysteine at the active site (4-5).

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The mammalian thioredoxin reductases (TrxRs) are a family of selenocysteine-containing pyridine nucleotide-disulfide oxidoreductases. All the mammalian TrxRs are homologous to glutathione reductase with respect to primary structure including the conserved redox catalytic site (-Cys-Val-Asn-Val-Gly-Cys-) but distinctively with a C-terminal extension containing a catalytically active penultimate selenocysteine (SeCys) residue in the conserved sequence(-Gly-Cys-SeCys-Gly). TrxR is homodimeric protein in which each monomer includes an FAD prosthetic group, a NADPH binding site and a redox catalytic site. Electrons are transferred from NADPH via FAD and the active-site disulfide to C-terminal SeCys-containing redox center, which then reduces the substrate like thioredoxin. The members of TrxR family are 55 – 58 kilodalton in molecular size and composed of three isoforms including cytosolic TrxR1, mitochondrial TrxR2, and TrxR3, known as Trx and GSSG reductase (TGR). TrxR plays a key role in protection of cells against oxidative stress and redox-regulatory mechanism of transcription factors and various biological phenomena (1).

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Nitrotyrosine has been identified as an indicator of cell damage and inflammation, as well as the production of NO. Nitrotyrosine is a relatively stable product formed from various reaction pathways. One of them is the reaction of peroxynitrite with tyrosine. Peroxynitrite formed from superoxide and nitric oxide radicals mediates tyrosine nitration reactions on proteins resulting in inactivation of certain house-keeping enzymes as well as endogenous antioxidant enzymes such as catalase and superoxide dismutase.
Nitrotyrosine has been implicated in the pathogenesis of many inflammatory, infectious and degenerative human diseases such as Alzheimer’s disease, atherosclerosis, asthma and a variety of conditions mediated by endothelial injury. Oxidative stress has been indicated as a mechanism of secondary neuronal injury in traumatic brain injury. Nitrotyrosine in the cerebrospinal fluid may be an in vivo marker of oxidative nitric oxide damage. Several pathologies of the cardiovascular system are also associated with an augmented production of nitric oxide and/or superoxide-derived oxidants that lead to nitroxidative stress. The high contents of iron (heme) in certain tissues such as heart and vascular smooth muscle cells could serve as a biological base for iron toxicity on free radical-mediated tissue damage, including formation of nitrotyrosine.

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Platelet-derived growth factors (PDGFs) have been implicated in the control of cell proliferation, survival and migration. The PDGF family of growth factors consists of five different disulphide-linked dimers built up of four different polypeptide chains encoded by four different genes. Theses isoforms, PDGF-AA, PDGF-AB, PDGF-BB, PDGF-CC and PDGF-DD, act via two receptor tyrosine kinases, PDGF receptors α and β. Thus far, gene-targeting experiments have been attempted to create knockout mice deficient for PDGFR-α or PDGFR-β. Those mice, however, died either at the embryonic stage or several days after birth. Platelet-derived growth factor receptors, PDGFR-α and PDGFR-β, have five extracellular immunoglobulin-like domains and an intracellular tyrosine kinase domain. Upon binding a PDGF, the receptors form homo- and heterodimers. Dimerization of the receptors juxtaposes the intracellular part of the receptors, which allow phosphorylation in trans between the two receptors in the complex. These autophosphorylation provide docking sites for downstream signal transduction molecules. More than 10 different SH2–domain-containing molecules have been shown to bind to different autophosphorylation sites in the PDGF α- and β-receptors. There are signal transduction molecules with enzymatic activity, such as PI3-kinase, PLC-γ, Src, SHP-2, GAP, as well as adaptor molecules such as Grb2, Shc, Nck, Grb7 and Crk, and Stats. Each of the different partners recruited by the activated receptor initiates different signaling pathways, making possible a great variety of cellular response.

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Anti-ANO1 (TMEM16A) Rabbit Polyclonal Antibody

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Cortactin is a ubiquitous actin-binding protein that was originally identified as a substrate for Src. It is accumulated in peripheral, actin-enriched structures of cells, including lamellipodia and membrane ruffles, suggesting that cortactin facilitates actin network formation. Cortactin has four major domains of interest:the N-terminal acidic (NTA) and tandem repeats domains, and the C-terminal proline-rich and SH3 Domains. NTA associates with the Arp2/3 and WASP complex at F-actin branches. Cortactin is involved in promoting cell motility and invasion, including a critical role in invadopodia, actin rich-subcellular protrusions associated with degradation of the ECM by cancer cells. Cortactin is phosphorylated by src family kinases at Y421, Y466, and Y482 and S405 and S418 that are phosphorylated by Erk family kinases.

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Ferritin is a ubiquitous and highly conserved protein which plays a major role in iron homeostasis. It is a holoenzyme shell (~450 kDa) consisting of 24 subunits of two types, H(heavy) and L(light), and capable of storing up to 4,500 atoms of ferric iron. Depending on the tissue type and physiologic status of the cell, the ratio of H to L subunits in ferritin can vary widely. It can be viewed not only as part of a group of iron regulatory proteins that include transferrin and the transferrin receptor, but also as a member of the protein family that orchestrates the cellular defense against stress and inflammation. Ferritin is found in the liver, spleen, kidney and heart. Only a small amount is found in the blood. The blood level of ferritin serves as an indicator of the amount of iron stored in the body.

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Cyclin-dependent kinase 7 (CDK7) has essential roles in the cell-division cycle as a CDK-activating kinase (CAK) and in the transcription as a component of the general transcription factor TFIIH.
This protein forms a trimeric complex with cyclin H and MAT1, which functions as a Cdk-activating kinase (CAK), phosphorylating cell-cycle CDKs. It is also an essential component of the transcription factor TFIIH, which phosphorylates the C-terminal domain (CTD) of the largest subunit of Pol II. This protein is thought to serve as a direct link between the regulation of transcription and the cell cycle.
Embryonic stem cells (ESCs) shows a very unusual cell cycle structure, characterized by a short G1 phase and a high proportion of cells in S-phase. This is associated with a unique mechanism of cell cycle regulation by the activity of cyclin dependent protein kinase (Cdk). The unique cell cycle structure and mechanism of cell cycle control indicates that the cell cycle machinery plays a role in establishment or maintenance of the stem cell state.

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Amphiphysins, members of the BAR (Bin-Amphiphysin-Rvsp) protein super family, play a key role in clathrin-mediated endocytosis of synaptic vesicles (SVs). All members of the BAR family share a highly conserved N-terminal BAR domain and a C-terminal Src homology (SH3) domain. Two isoforms of amphiphysin have been identified and act in concert as a heterodimer. Amphiphysins interact via its carboxy-terminal SH3 domain with dynamin, synaptojanin and clathrin. These complexes are implicated in synaptic vesicle recycling at nerve terminal.  Amphiphysins were also identified as the dominant autoantigen in paraneoplastic Stiff-Man Syndrome.

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Catalase is a homotetrameric heme-containing enzyme present within the matrix of all peroxisomes. It carries out a dismutation reaction in which hydrogen peroxide is converted to water and oxygen. Human catalase has the last four amino acids (-KANL) at the extreme C-terminus for peroxisome targeting. The monomer of human catalase is 61.3 kD in molecular size. Catalase has been implicated as an important factor in inflammation, mutagenesis, prevention of apoptosis, and stimulation of a wide spectrum of tumors. Loss of catalase leads to the human genetic disease, acatalasemia, or Takahara’s disease (1).

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Heat shock proteins are ubiquitous proteins and have been characterized as cytoprotective molecular chaperones. The typical function of a chaperone is to assist a protein to attain its functional conformation to prevent non-functional aggregation of misfolded proteins. The principal HSP families are HSP90, HSP70, HSP60 and the small HSPs including HSP27, ubiquitin, α-crystallin, Hsp20 and others. The common functions of small Hsps are chaperone activity, thermotolerance, inhibition of apoptosis, regulation of cell development, and cell differentiation.
Hsp27 has a molecular weight of approximately 27 kDa, although it has been shown to form large aggregates of up to 800 kDa in the cytosol. Hsp27 is found in several types of human cells, including tumour cells. Hsp27 interferes with apoptosis through its ability to interact with and inhibit key components of the apoptotic signaling pathway, including the caspase activation complex. Overexpression of heat shock proteins can increase the tumorigenic potential of tumour cells. HSP27 also has been reported to be involved in development and progression of hormone-refractory prostate cancer.

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Anti-Insulin Rabbit Polyclonal Antibody

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Protein-tyrosine phosphatase 14 (PTPN14/PTPD2/PEZ) is a 130kDa multidomain cytosolic protein, and belongs to the NT6 subtype of PTPs.
It is characterized by an N-terminal FERM domain (Band 4.1, ezrin, radixin, moesin homology) and a C-terminal PTP domain. Pez(Phosphatase with ezrin domain) may play a role in regulating endothelial cell proliferation during vascular injury and angiogenesis. B-Catenin, a central component of adherens junctions, has been identified as a PTPN14 substrate. TGF, which inhibits cell proliferation but not migration, also inhibits translocation of PTPN14 from the cytosol to the nucleus.

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Receptor-type tyrosine-protein phosphatase eta(Also known as DEP1; SCC1; CD148; HPTPeta; R-PTP-ETA) is an enzyme that in humans is encoded by the PTPRJ gene.[1][2][3]
The protein encoded by this gene is a member of the protein tyrosine phosphatase (PTP) family. PTPs are known to be signaling molecules that regulate a variety of cellular processes including cell growth, differentiation, mitotic cycle, and oncogenic transformation. This PTP possesses an extracellular region containing five fibronectin type III repeats, a single transmembrane region, and a single intracytoplasmic catalytic domain, and thus represents a receptor-type PTP. This PTP is present in all hematopoietic lineages, and was shown to negatively regulate T cell receptor signaling possibly through interfering with the phosphorylation of Phospholipase C Gamma 1 (PLCG1) and Linker for Activation of T Cells (LAT). This PTP was also found to dephosphorylate PDGF beta receptor, and may be involved in UV-induced signal transduction.[3]
PTPRJ has been shown to interact with CTNND1.[4]

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Casein kinases are a group of ubiquitous Ser/Thr kinases that phosphorylate key regulatory proteins involved in the control of cell differentiation, proliferation, chromosome segregation, circadian rhythms, and metabolic pathways. CK1 family members share a highly conserved kinase domain but differ in their variable N- and C-terminal domains. Mammals have seven family members: α, β, γ1, γ2, γ3, δ, and ε. They all share at least 50% amino acid identity within the protein kinase catalytic domain. CK1 isoforms exclusively use ATP as phosphate donor and are generally co-factor independent.
Casein kinase 1 δ is ubiquitously expressed in all tissues, is p53 dependently induced in stress situations and plays an important role in various cellular processes. PKA phosphorylates CK1δ, predominantly at Ser370 in vitro and in vivo, and that site-specific phosphorylation of CK1δ by PKA plays an important role in modulating CK1δ-dependent processes.

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Sequential activation of protein kinases within the MAPK (mitogen-activated protein kinases) cascades is a common mechanism of signal transduction in many cellular processes. The ERK signaling cascade is a central MAPK pathway that plays a role in the regulation of various cellular processes such as proliferation, differentiation, development, learning, and survival. Mitogen-activated protein kinase kinases (MAPKK) phosphorylate MAPK. MEK (MAP kinase or ERK kinase) is the immediate upstream activator kinase of ERK.
The human MEK3 encodes 347 amino acid residues. MEKs (MEK1, MEK2, MEK3) show remarkably different activity toward ERKl and ERK2. MEK2 is the most active ERK activator. MEK3 is inactive toward ERKl or ERK2. MEK3, MEK4, and MEK6 phosphorylate and activate p38 MAP kinase. The p38 mitogen-activated protein (MAP) kinase signal transduction pathway is activated by proinflammatory cytokines and environmental stress. Transcription factors such as ATF2 and Elk-1 are targets of the p38 MAP kinase signal transduction pathway.

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The Smad family of proteins are functioning in the transmission of extracellular signals in the TGF-β signaling pathway. Binding of a TGF-β superfamily ligands to extracellular receptors triggers phosphorylation of Smad2 at a Serine-Serine-Methionine-Serine (SSMS) motif at its C-terminus. Phosphorylated Smad2 is then able to form a complex with Smad4. These complexes accumulate in the cell nucleus, where they are directly participating in the regulation of gene expression.
In mammals, eight Smad proteins have been identified to date. The Smad family of proteins can be divided into three functional groups: the receptor-activated Smads (R-Smads), common mediator Smads (Co-Smads), and the inhibitory Smads (I-Smads). The R-Smads are directly phosphorylated by the activated type I receptors on their C-terminal Ser-Ser-X-Ser (SSXS) motif and include Smad1, Smad2, Smad3, Smad5, and Smad8. Smad2 and Smad3 are phosphorylated in response to TGF-β and activin, whereas Smad1, Smad5, and Smad8 are phosphorylated in response to BMP (Bone Morphogenetic Protein). This C-terminal phosphorylation allows R-Smad binding to Co-Smad, Smad4, and translocation to the nucleus where they regulate TGF-β target genes. Smad6 and Smad7 belong to the I-Smad which bind to the type I receptor or Smad4 and block their interaction with R-Smads.
The Smads share sequence similarities, most notably in the N-terminal and carboxy-terminal regions, referred to as the MH1 (Mad Homology 1) and MH2 domains respectively. Smad2 and Smad3 have 66% amino acid sequence identity between their MH1 domains and 96% amino acid sequence identity between their MH2 domains.

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T cell protein tyrosine phosphatase (TCPTP), also known as PTPT and PTPN2, is an enzyme that removes phosphate groups covalently attached to tyrosine residues in proteins. TCPTP is ubiquitously expressed with particularly high expression in hematopoietic tissues and exists as two forms: an endoplasmic reticulum-targeted 48-kDa form (TC48) and a nuclear 45-kDa form (TC45). Although targeted to the nucleus, TC45 can exit in response to specific stimuli to dephosphorylate cytoplasmic substrates. TC-PTP is a negative regulator of the Jak/Stat cytokine signaling pathway. TCPTP is the PTP most closely related to PTP1B, with 72% sequence identity and 86% similarity in the catalytic domain.

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Ubiquitin+1(Ub+1) is a novel mutant form of ubiquitin that can be produced through a process known as molecular frame shift. Ub+1 can be polyubiquitinated to produce aberrant polyubiquitin chains that inhibit the 26S proteasome. Especially ub+1 is accumulated in aggregates containing amyloid-β and phosphorylated-tau. Elevated expression of Ub+1 mRNA and protein has been observed in the brains of patients with Alzheimer's disease. Also Ub+1 acts as an aggravating factor in polyglutamine-induced neurodegeneration.

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Connexin 43(Cx43) is a widely expressed gap junction protein that
mediates communication between many cell types. Gap junctions are
implicated in tissue homeostasis and control of cell proliferation and
differentiation. Connexin 43 is predominantly localized at the sarcolemma,
where six connexins assemble into a so-called connexon or hemichannel.
Clusters of these channels assemble to make gap junctions. Cx43 is a
target protein of several kinases, among them PKA, PKC, PKG, MAPK,
and casein kinase, but also for protein phosphatases. The
phosphorylation of Cx43 at Ser368 by PKC induces a closure of
Hemichannels. Src can phosphorylate Cx43 to alter gap junction
communication.

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The mammalian thioredoxin reductases (TrxRs) are a family of selenocysteine-containing pyridine nucleotide-disulfide oxido-reductases. All the mammalian TrxRs are homologous to glutathione reductase with respect to primary structure including the conserved redox catalytic site (-Cys-Val-Asn-Val-Gly-Cys-) but distinctively with a C-terminal extension containing a catalytically active penultimate selenocysteine (SeCys) residue in the conserved sequence(-Gly-Cys-SeCys-Gly). TrxR is homodimeric protein in which each monomer includes an FAD prosthetic group, a NADPH binding site and a redox catalytic site. Electrons are transferred from NADPH via FAD and the active-site disulfide to C-terminal SeCys-containing redox center, which then reduces the substrate like thioredoxin. The members of TrxR family are 55 – 58 kilodalton in molecular size and composed of three isoforms including cytosolic TrxR1, mitochondrial TrxR2, and TrxR3, known as Trx and GSSG reductase (TGR). TrxR plays a key role in protection of cells against oxidative stress and redox-regulatory mechanism of transcription factors and various biological phenomena (1).

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Peroxiredoxin (Prx) is a growing peroxidase family, whose mammalian members have been known to connect with cell proliferation, differentiation, and apoptosis.
Many isoforms (about 50 proteins), collected in accordance to the amino acid sequence homology, particularly amino-terminal region containing active site cysteine residue, and the thiol-specific antioxidant activity, distribute throughout all the kingdoms. Among them, mammalian Prx consists of 6 different members grouped into typical 2-Cys, atypical 2-Cys Prx, and 1-Cys Prx. Except Prx VI belonging to 1-Cys Prx subgroup, the other five 2-Cys Prx isotypes have the thioredoxin-dependent peroxidase (TPx) activity utilizing thioredoxin, thioredoxin reductase, and NADPH as a reducing system. Mammalian Prxs are 20 – 30 kilodalton in molecular size and vary in subcellular localization: Prx I, II, and VI in cytosol, Prx III in mitochondria, Prx IV in ER and secretion, Prx V showing complicated distribution including peroxisome, mitochondria and cytosol (1).

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Peroxiredoxin (Prx) is a growing peroxidase family, whose mammalian members have been known to connect with cell proliferation, differentiation, and apoptosis.
Many isoforms (about 50 proteins), collected in accordance to the amino acid sequence homology, particularly amino-terminal region containing active site cysteine residue, and the thiol-specific antioxidant activity, distribute throughout all the kingdoms. Among them, mammalian Prx consists of 6 different members grouped into typical 2-Cys, atypical 2-Cys Prx, and 1-Cys Prx. Except Prx VI belonging to 1-Cys Prx subgroup, the other five 2-Cys Prx isotypes have the thioredoxin-dependent peroxidase (TPx) activity utilizing thioredoxin, thioredoxin reductase, and NADPH as a reducing system. Mammalian Prxs are 20 – 30 kilodalton in molecular size and vary in subcellular localization: Prx I, II, and VI in cytosol, Prx III in mitochondria, Prx IV in ER and secretion, Prx V showing complicated distribution including peroxisome, mitochondria and cytosol.

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Glutamine Synthetase(GS) catalyzes the conversion of ammonia and glutamate to glutamine. This reaction consumes a molecule of ATP:
Glutamate + NH4+ + ATP
 Glutamine + ADP + Pi
GS is found in astrocytes as an octamer of identical 45kDa subunits. Most well known function of GS is the detoxification of brain ammonia. It also has an important role in controlling metabolic regulations of neurotransmitter glutamate. Because of the multiple functions and importance of GS in cellular metabolism, both catalytic activities and synthesis are highly regulated. The activity of GS is controlled by adenylylation. Its activity is decreased in the cerebral cortex of brains affected by Alzheimer’s disease, particularly in the vicinity of senile plaques. It is also decreased under conditions of glucose deprivation. On the other hands, the level of expression of GS is increased during ischemia in vivo or hypoxia in culture.

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Peroxiredoxin (Prx) is a growing peroxidase family, whose mammalian members have been known to connect with cell proliferation, differentiation, and apoptosis. Many isoforms (about 50 proteins), collected in accordance to the amino acid sequence homology, particularly amino-terminal region containing active site cysteine residue, and the thiol-specific antioxidant activity, distribute throughout all the kingdoms. Among them, mammalian Prx consists of 6 different members grouped into typical 2-Cys, atypical 2-Cys Prx, and 1-Cys Prx. Except Prx VI belonging to 1- Cys Prx subgroup, the other five 2-Cys Prx isotypes have the thioredoxindependent peroxidase (TPx) activity utilizing thioredoxin, thioredoxin reductase, and NADPH as a reducing system. Mammalian Prxs are 20 – 30 kilodalton in molecular size and vary in subcellular localization: Prx I, II, and VI in cytosol, Prx III in mitochondria, Prx IV in ER and secretion, Prx V showing complicated distribution including peroxisome, mitochondria and cytosol.

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Antithrombin III is a plasma protein synthesized in the liver and has molecular weight of 58kDa. Antithrombin III is a heparin-binding glycoprotein that acts as the major inhibitor of thrombin. Also it interferes with several plasma proteases, including kallikrein and factors IXa, Xa, XIa and XIIa, thereby playing a central role in regulating coagulation. It is also used as a therapeutic agent in patients with sepsis and disseminated intravascular coagulation. In addition, a number of recent studies have shown that antithrombin III has anti-inflammatory properties, which are independent of its effects on coagulation.

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Anti-PRDX-SO3 Mouse Monoclonal Antibody [clone: 10A1]

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The Heat shock protein 70(HSP70) family was found in many intracellular compartments. Members of this protein occur in chloroplasts, endoplasmic reticulum, mitochondria, and cytosol. These proteins are induced by a variety of biological stresses, including heat stress, in every organism. HSP70 serves a variety of roles: 1) It acts as molecular chaperones facilitating the assembly of multi-protein complexes, 2) It participates in the translocation of polypeptides across cell membranes and to the nucleus 3) It aids in the proper folding of nascent polypeptide chains. HSP70 is mitochondrial import machinery and plays key roles in the cytosolic endoplasmic reticulum. Recently, extracellular localized HSP have been found to play key roles in the induction of a cellular immune response.