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Artikel-Nr: (ABFRLF-MA0055)

Lieferant: AbFrontier

Hersteller Artikel Nummer : LF-MA0055

Beschreibung: 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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Artikel-Nr: (ABFRLF-MA0244)

Lieferant: AbFrontier

Hersteller Artikel Nummer : LF-MA0244

Beschreibung: The piwi gene of Drosophila belongs to a novel class of evolutionarily conserved genes (the piwi or Argonaute family). The Piwi family‘ is required for germ- and stem-cell development in invertebrates, and two Piwi members, MIWI and MILI (Miwi like; Piwil2; Piwi-like protein 2), are essential for spermatogenesis in mouse. MIWI and MILI partner with Piwi-interacting RNAs (piRNAs) which are 26–31 nucleotides (nt) in length—clearly distinct from the 21–23 nt of microRNAs (miRNAs) or short interfering RNAs (siRNAs).
A search for murine small RNAs that might program Piwi proteins for transposon suppression revealed developmentally regulated piRNA loci, some of which resemble transposon master control loci of Drosophila. MILI might be programmed by distinct piRNA populations at different stages of germ cell development, suggesting MILI plays an important role in meiotic prophase progression.

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Artikel-Nr: (ABFRLF-MA0090)

Lieferant: AbFrontier

Hersteller Artikel Nummer : LF-MA0090

Beschreibung: 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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Artikel-Nr: (ABFRLF-MA0243)

Lieferant: AbFrontier

Hersteller Artikel Nummer : LF-MA0243

Beschreibung: Myoglobin is a cytoplasmic hemoprotein, expressed solely in cardiac myocytes and oxidative skeletal muscle fibers, that reversibly binds O2 by its heme (iron-containing porphyrin) prosthetic group in the center around which the remaining apoprotein folds. The red color that meat takes is partly determined by the charge of the iron atom in myoglobin and the oxygen attached to it. When meat is in its raw state, the iron atom has a charge of +2 and is bound to an oxygen molecule.
Myoglobin is a single-chain globular protein of 153 amino acids and has a molecular weight of 16,700 daltons. Unlike the blood-borne hemoglobin, to which it is structurally related, this protein does not exhibit cooperative binding of oxygen, since positive cooperaivity is a property of multimeric/oligomeric proteins only.
Recent gene disruption studies using the myoglobin deficient mouse model support the conclusion that the functions of myoglobin include: facilitated oxygen transport, the storage of oxygen and a scavenger of nitric oxide or reactive oxygen species.
Myoglobin is an early indicator of cardiac ischemia that achieves maximal sensitivity 3 to 4 hours after symptom onset. However, it is only marginally more sensitive than CK-MB early after the onset of symptoms, and it is less sensitive 6 to 8 hours after symptom onset. Because of rapid clearance from the blood, myoglobin may "miss" late-presenting patients, and it is less cardiospecific than CK-MB.

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Artikel-Nr: (ABFRLF-MA0249)

Lieferant: AbFrontier

Hersteller Artikel Nummer : LF-MA0249

Beschreibung: 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 MEK1 encodes 393 amino acid residues and shares 99% amino acid sequence identity with the murine MEKl and 80% with human MEK2 (400 amino acids). The MEKs constitute an evolutionarily conserved group of three highly homologous mammalian isoforms. These are the 45 kDa MEK1, its alternatively spliced form, MEK1b (43 kDa) that is thought to be inactive, and the 46 kDa MEK2. These proteins are composed of a catalytic kinase domain, which is surrounded by a regulatory N-terminal domain ( 80 amino acids) and a shorter C-terminal region ( 30 amino acids). MEKs are activated by phosphorylation of two Ser residues in their activation loop (Ser218 and Ser222 in MEK1). The activity of MEKs is regulated by additional phosphorylation/dephosphorylation processes as well.

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Artikel-Nr: (ABFRLF-MA0291)

Lieferant: AbFrontier

Hersteller Artikel Nummer : LF-MA0291

Beschreibung: 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.
MEK6 encodes a 334-amino acid protein with 82% identity to MKK3. MEK6 is highly expressed in skeletal muscle like many other members of this family, but in contrast to MKK3 its expression in leukocytes is very low. The human 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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Artikel-Nr: (ABFRLF-MA0341)

Lieferant: AbFrontier

Hersteller Artikel Nummer : LF-MA0341

Beschreibung: Lactate dehydrogenase (LDH) is the enzyme in the glycolytic pathway that converts pyruvate to lactate with concomitant interconversion of NADH and NAD+. In mammals, the enzyme is encoded by three genes: LDHA (M or muscle form), LDHB (H or heart form), and LDHC (X or testis form). The three human LDHs have 84–89% sequence similarities and 69–75% amino acid identities. There are five different LDH isoenzymes based on the proportion of M and H chains existing in the LDH tetrameric structure.
The LDHA is hypoxia inducible and its expression is directly controlled by the transcriptional activity of the hypoxia inducible factor 1a (HIF1a). LDHB is also known to be upregulated in many cancers.

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Artikel-Nr: (ABFRLF-PA0205)

Lieferant: AbFrontier

Hersteller Artikel Nummer : LF-PA0205

Beschreibung: 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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Artikel-Nr: (ABFRLF-PA0178)

Lieferant: AbFrontier

Hersteller Artikel Nummer : LF-PA0178

Beschreibung: Bcl-2 (B-cell lymphoma 2) family govern mitochondrial outer membrane permeabilization (MOMP) and can be either pro-apoptotic (Bax, BAD, Bak and Bok) or anti-apoptotic (Bcl-2, Bcl-xL, and Bcl-w). The mitochondrial release of cytochrome c through anion channel is regulated by Bcl-2 and Bcl-xL. The Bcl-2 family of proteins are key regulators of many signals leading to caspase, which when activated cause cellular destruction by cleaving a range of vital cellular substrates.
The members of the Bcl-2 family share one or more of the four characteristic domains of homology entitled the Bcl-2 homology (BH) domains (named BH1, BH2, BH3 and BH4).
The Bcl-2 gene has been implicated in a number of cancers, including melanoma, breast, prostate, and lung carcinomas, as well as schizophrenia and autoimmunity. It is also thought to be involved in resistance to conventional cancer treatment.
Apoptosis is an important component of the sequence of events during which anticancer drugs induce an antitumor response. The molecular mechanism for drug-induced apoptosis is associated with a mitochondrial dysfunction that is characterized by an increase in MOMP and a release of cytochrome c from mitochondria, indicating that Bcl-2 plays a critical role in anticancer drug-induced apoptosis.

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Lieferant: AbFrontier

Beschreibung: 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.

Artikel-Nr: (ABFRLF-PA0218)

Lieferant: AbFrontier

Hersteller Artikel Nummer : LF-PA0218

Beschreibung: 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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Artikel-Nr: (ABFRLF-PA0175)

Lieferant: AbFrontier

Hersteller Artikel Nummer : LF-PA0175

Beschreibung: Protein kinase C (PKC) is a family of serine-threonine kinases that regulate a broad spectrum of cellular functions. The family is composed of nine genes that express structurally related phospholipid-dependent kinases with distinct means of regulation and tissue distribution. Based on their structures and sensitivities to Ca2+ and diacylglycerol (DAG), they have been classified into conventional PKCs (α, β, and γ), novel PKCs (δ, ε, η, and θ), and atypical PKCs (ζ and λ/ι).
Mammalian PKC α consists of 672 amino acids and is distributed in all tissues, in contrast to other PKC isotypes whose expression is restricted in the particular tissues. PKC α is activated by a variety of stimuli originating from receptor activation, cell contact and physical stresses. Kinase activity of PKC α is regulated by phosphorylation of three conserved residues in its kinase domain: the activation-loop site Thr-497, the autophosphorylation site Thr-638, and the hydrophobic C-terminal site Ser-657. In some types of cells, PKC α is implicated in cell growth, in contrast, it may play a role in cell cycle arrest and differentiation in other types of cells. The responses are modulated by dynamic interactions with cell-type specific factors.

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Artikel-Nr: (ABFRLF-PA0200)

Lieferant: AbFrontier

Hersteller Artikel Nummer : LF-PA0200

Beschreibung: 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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Artikel-Nr: (ABFRLF-PA0186)

Lieferant: AbFrontier

Hersteller Artikel Nummer : LF-PA0186

Beschreibung: The epidermal growth factor receptor (EGFR) is a transmembrane receptor tyrosine kinase of the ErbB (also known as HER) family in which four members have been identified: EGFR (ErbB1), HER2/Neu (ErbB2), HER3 (ErbB3), and HER4 (ErbB4). All four erbB receptors are composed of an extracellular ligand-binding region consisting of glycosylated domains, a transmembrane domain containing a single hydrophobic anchor sequence, an intracellular region containing the catalytic tyrosine kinase domain, and a carboxyl-terminal region containing several tyrosine residues that become phosphorylated after receptor activation.
The epidermal growth factor receptor (EGFR) signaling pathway is one of the most important pathways that regulate growth, survival, proliferation, and differentiation in mammalian cells. EGFR and other members of the erbB family form either homodimers or heterodimers upon ligand binding, resulting in conformational changes that allow activation of protein kinases and transphosphorylation of key tyrosine residues within the carboxyl-terminal domain. After the induction of tyrosine phosphorylation, some signaling pathways appear to start with the recognition of the C-terminal phosphotyrosines by appropriate adaptor or signaling molecules.
The aberrant activation of the EGFR leads to enhanced proliferation and other tumor-promoting activities. Several mechanisms lead to aberrant receptor activation, including receptor overexpression, gene amplification, activating mutations, overexpression of receptor ligands, and/or loss of their negative regulatory mechanisms.
The epidermal growth factor receptor (EGFR) has been extensively investigated as a target for anti-neoplastic therapy. Anti-EGFR antibodies that interfere with ligand-dependent receptor activation have shown clinical activity in a variety of solid tumors.

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Artikel-Nr: (ABFRLF-PA0203)

Lieferant: AbFrontier

Hersteller Artikel Nummer : LF-PA0203

Beschreibung: 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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Artikel-Nr: (ABFRLF-PA0024)

Lieferant: AbFrontier

Hersteller Artikel Nummer : LF-PA0024

Beschreibung: 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).

UOM: 1 * 0,1 mL

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