Cayman Chemical New Products

07-24 · 13,14-dihydro-15-keto Prostaglandin A2 Lipid Maps MS Standard

PGE2 is metabolized rapidly to 13,14-dihydro-15-keto PGE2, which is present in the plasma of humans and other mammals. 13,14-dihydro-15-keto PGA2 results from the non-enzymatic dehydration of 13,14-dihydro-15-keto PGE2, a process which is accelerated by the presence of albumin. Further decomposition of 13,14-dihydro-15-keto PGA2 by the intentional addition of base produces bicyclo PGE2, a stable marker of PGE2 biosynthesis.

07-24 · EUK 124

EUK 8 and EUK 134 are synthetic catalytic scavengers of reactive oxygen species with superoxide dismutase (SOD) and catalase mimetic activity. EUK 124 is a structural analog of EUK 8 and EUK 134 with significantly reduced activity. EUK 124 and EUK 8 inhibit superoxide-mediated reduction of an electron acceptor (i.e. SOD mimetic activity), with IC50 values of 5 µM and 0.7 µM, respectively.

07-24 · LY223982

Leukotriene B4 (LTB4) is a dihydroxy fatty acid derived from the 5-lipoxygenase (5-LO) pathway of arachidonic acid metabolism and is an important mediator of the inflammatory process. The benzophenone dicarboxylic acid derivative LY223982 is a potent BLT1 receptor antagonist. It inhibits the specific binding of radiolabeled-LTB4 to isolated human neutrophils with an IC50 value of 13.2 nM. LY223982 inhibits the LTB4-induced aggregation of guinea pig and human neutrophils with IC50 values of 74 and 100 nM, respectively. However, concentrations of LY223982 up tp 10 µM do not inhibit binding of LTB4 to human BLT1 or BLT2 expressed in CHO cells.

07-23 · 16(S)-HETE

Electrolyte and fluid transport in the kidney are regulated in part by arachidonic acid and its metabolites. 16-HETE is a minor CYP450 metabolite of arachidonic acid released by the kidney upon angiotensin II stimulation that demonstrates stereospecific biological activity. 16(S)-HETE inhibits proximal tubule ATPase activity by as much as 60% at a concentration of 2 µM.

07-23 · ApoB (human) EIA Kit

Apolipoprotein B (ApoB) is the main apolipoprotein of chylomicrons and low density lipoproteins (LDL). The protein exists as two main isoforms, ApoB-48 and ApoB-100. In humans, ApoB-48 and ApoB-100 are synthesized exclusively by the small intestine and liver, respectively. Elevated plasma concentrations of ApoB and LDL are established risk factors for atherosclerotic coronary disease. Cayman’s Human ApoB EIA Kit is an immunometric (i.e., “sandwich”) assay which can be used to measure ApoB in plasma and serum without prior sample purification. This assay also can be used to detect cellular ApoB levels in cell lysate samples. The standard curve spans the range of 0-160 ng/ml with a limit of detection of approximately 10 ng/ml.

07-23 · CD34 Monoclonal FITC Antibody (Clone ICO-115)

This CD34 monoclonal antibody recognizes an extracellular carbohydrate epitope of CD34. CD34 is a type I transmembrane glycoprotein (Mr = 104-120 kDa) expressed on stem cells, early hematopoietic progenitor cells, bone marrow stroma cells, endothelial cells, embryonic fibroblasts, and neurons. CD34 analysis can be used for the differential identification of acute leukemias as well as routine analysis of cultured stem cell lines.

07-17 · Combrestatin A4 3'-O-Phosphate

Combretastatin A4 (CA4) is a potent inhibitor of tubulin polymerization that displays strong inhibitory activity on tumor cell growth. Combretastatin-A-4-3’-O-Phosphate (CA4P) is a CA4 prodrug that inhibits tumor growth in several cell lines including P-388 (leukemia), SK-N-SH (neuroblast), BXPC-3 (pancreas), NCI-H460 (lung), and DU-145 (prostate) with ED50 values of 0.0029, 0.00025, 0.23, 0.00035, and 0.00072 µg/ml, respectively. CA4P specifically targets the tumor vasculature. In a rat model of carcinosarcoma, CA4P delivered intraperitoneally at a dose of 100 mg/kg effectively disrupts tumor blood flow within six hours after administration without significantly affecting normal tissues.

07-17 · H-8 (hydrochloride)

The H series isoquinolinesulfonamide protein kinase inhibitors are widely used to block signaling pathways to elucidate mechanisms of cellular regulation and signal transduction. H-8, an isoquinolinesulfonamide protein kinase inhibitor, is a potent inhibitor of PKA and PKG and shows moderate inhibition for PKC and MLCK with Ki values of 1.2, 0.48, 15, and 68 µM, respectively. H-8 can disrupt transcriptional elongation by inhibiting cyclin C/CDK8 and cyclin H/CDK7/p36 CTD kinase activity with IC50 values of 47 and 6.2 µM, respectively.

07-17 · Protein Phophatase 2A C subunit (human recombinant; L309 deletion)

Reversible protein phosphorylation is a fundamental regulatory mechanism in all aspects of biology. Protein phosphatase 2A (PP2A) is a divalent cation-independent protein serine/threonine phosphatase involved in regulating numerous cellular processes including the cell cycle, growth and differentiation and is also thought to be a potential tumor suppressor. PP2A is a hetrotrimeric protein containing a 65 kDa scaffolding A subunit, a regulatory B subunit and a 36-kDa catalytic C subunit. The recombinant PP2A catalytic subunit has the characteristic properties of Type 2A phosphatases and is highly sensitive to okadaic acid and microcystins. The provided preparation of the catalytic subunit of PP2A is useful for the study of enzyme kinetics and regulation, to dephosphorylate target substrates and to evaluate the effects of test substances on the activity of the phosphatase.

07-17 · Protein Phosphatase 2A C subunit (human recombinant)

Reversible protein phosphorylation is a fundamental regulatory mechanism in all aspects of biology. Protein phosphatase 2A (PP2A) is a divalent cation-independent protein serine/threonine phosphatase involved in regulating numerous cellular processes including the cell cycle, growth, and differentiation and is thought to be a potential tumor suppressor. PP2A is a hetrotrimeric protein containing a 65 kDa scaffolding A subunit, a regulatory B subunit, and a 36 kDa catalytic C subunit. The recombinant PP2A catalytic subunit has the characteristic properties of Type 2A phosphatases and is highly sensitive to okadaic acid and microcystins. The provided preparation of the catalytic subunit of PP2A is useful for the study of enzyme kinetics and regulation, to dephosphorylate target substrates and to evaluate the effects of test substances on the activity of the phosphatase.

07-16 · Mevastatin

HMG-CoA reductase is the rate-limiting enzyme in the cholesterol biosynthetic pathway and the target of the “statin” class of cholesterol-lowering drugs. Mevastatin is a HMG-CoA reductase inhibitor that was initially isolated from the mold Pythium ultimum. It inhibits HMG-CoA reductase in a reversible and competitive manner with a Ki value of 1 nM for the open ring acid form of the molecule. During a 24 week study period, a dose of 30 mg/day mevastatin reduced plasma LDL-cholesterol approximately 29% in patients with familial hypercholesterolemia. Mevastatin also suppresses TNF-induced NF-κB activation (IC50 = ~17 µM), which potentiates apoptosis in human myeloid leukemia cells and thus, may be useful in treating cancer.

07-14 · CAY10550

Cellular prion protein (PrPc) is a cell surface glycoprotein expressed in brain, spinal cord, and several peripheral tissues that if mutated to the protease-resistant isoform PrPSc (scrapie PrP; PrPres) can result in one of several fatal neurodegenerative diseases. Prion diseases, including mad cow disease (bovine spongiform encephalopathy), scrapie, and Creutzfeldt-Jakob disease develop from the accumulation of PrPSc, an abnormally folded β-rich conformation of PrPc. CAY10550 is a potent antiprion compound that inhibits the accumulation of PrPc with an IC50 value of 3 nM in both ScN2a and F3 prion-infected murine neuroblastoma cell lines. This compound also demonstrates moderate radical scavenging activity as it inhibits the formation of hydroxyl radicals in vitro with an IC50 value of 0.09 mM.

07-08 · COX Fluorescent Inhibitor Screening Assay Kit

Cyclooxygenase (COX, also called Prostaglandin H Synthase or PGHS) is a bifunctional enzyme exhibiting both COX and peroxidase activities. The COX component converts arachidonic acid to a hydroperoxy endoperoxide (PGG2), and the peroxidase component reduces the endoperoxide to the corresponding alcohol (PGH2), the precursor of PGs, thromboxanes, and prostacyclins. It is now well established that there are two distinct isoforms of COX, COX-1 and COX-2. Cayman's COX Fluorescent Inhibitor Screening Assay provides a convenient fluorescence-based method for screening ovine COX-1 and human recombinant COX-2 for isozyme-specific inhibitors. The assay utilizes the peroxidase component of COXs. In this assay, the reaction between PGG2 and ADHP (10-acetyl-3,7-dihydroxyphenoxazine) produces the highly fluorescent compound resorufin. Resorufin fluorescence can be analyzed with an excitation wavelength of 530-540 nm and an emission wavelength of 585-595 nm.

07-08 · H-89

Protein kinase A (PKA) regulates multiple signal transduction events via protein phosphorylation and is integral to all cellular responses involving the cyclic AMP second messenger system. H-89 is a potent, cell permeable inhibitor of PKA that demonstrates an IC50 value of 0.14 µM and a Ki value of 48 nM in standard kinase assays. While widely used to disrupt PKA signaling, the inhibitory activity of H-89 is non-selective. H-89 also inhibits S6K1, MSK1, ROCK-II, PKBα, and MAPKAP-K1b with IC50 values of 0.08, 0.12, 0.27, 2.6, and 2.8 µM, respectively.

07-08 · HDBA

HDBA, a derivative of a Streptomyces griseolavendus butyl acetate extract, is a potent inhibitor of epidermal growth factor (EGF) receptor-associated tyrosine kinase with an IC50 value of 0.012 µM. HDBA also inhibits pp60c-src(+) kinase and Ca2+ calmodulin-dependent kinase II with IC50 values of 0.5 and 0.2 µM, respectively. At a concentration of 10-150 µM, HDBA inhibits tyrosine kinase-associated neutrophil degranulation and superoxide generation.

07-08 · Serum Retinol Binding Protein Western Ready Control

Human serum retinol binding protein 4 (sRBP4) binds to one equivalent of vitamin A and is one of the major retinol carriers found in the blood of mammals. Humans RBP4 is a monomeric 21 kDa β-sheet-rich protein that contains three disulfide bonds and belongs to the lipocalin protein family. sRBP4 is synthesized and sequestered in hepatocytes until retinol binding triggers its secretion . In plasma, sRBP4 typically forms a 1:1 complex with the 55 kDa tetrameric protein transthyretin (TTR) which prevents RBP from being removed from the plasma by glomerular filtration. Studies have shown that sRBP4 is an adipocyte-derived ‘signal’ that may contribute to the pathogenesis of type 2 diabetes. 14371,14380} Elevation of sRBP4 causes systemic insulin resistance whereas reduction of serum concentrations improves insulin action.

07-08 · U-83836E

U-83836E is an antioxidant which inhibits iron-dependent lipid peroxidation in rat brain with an IC50 value of 0.6 µM. This free radical scavenger has potent neuroprotective effects against ischemic injury and diabetic neuropathy. However at higher doses, U-83836E is highly cytotoxic. It reduces viability of rat brain endothelial cells (RBE4) with an IC50 value of 0.032 mM.

07-07 · Hsp90 Polyclonal Antibody

Hsp90 is a highly conserved and essential stress protein that is expressed in all eukaryotic cells. From a functional perspective, Hsp90 participates in the folding, assembly, maturation, and stabilization of specific proteins as an integral component of a chaperone complex. Despite its label of being a heat shock protein, Hsp90 is one of the most highly expressed proteins in unstressed cells (1-2% of cytosolic protein). It carries out a number of housekeeping functions-including controlling the activity, turnover, and trafficking of a variety of proteins. Most of the Hsp90-regulated proteins that have been discovered to date are involved in cell signaling. The number of proteins now known to interact with Hsp90 is about 100. Target proteins include the kinases v-Src, Wee1, and c-Raf, transcriptional regulators such as p53 and steroid receptors, and the polymerases of the hepatitis B virus and telomerase. When bound to ATP, Hsp90 interacts with co-chaperones Cdc37, p23, and an assortment of immunophilin-like proteins, forming a complex that stabilizes and protects target proteins from proteasomal degradation. In most cases, Hsp90-interacting proteins have been shown to co-precipitate with Hsp90 when carrying out immunoadsorption studies, and to exist in cytosolic heterocomplexes with it. In a number of cases, variations in Hsp90 expression or Hsp90 mutation has been shown to degrade signaling function via the protein or to impair a specific function of the protein (such as steroid-binding, kinase activity) in vivo. Ansamycin antibiotics, such as geldanamycin and radiciol, inhibit Hsp90 function.

07-07 · Hsp90β Monoclonal Antibody

07-07 · Tyrosine Hydroxylase (Phospho-Ser40) Polyclonal Antibody

Tyrosine hydroxylase (TH) is the rate-limiting enzyme in the synthesis of the catecholamines dopamine and norepinephrine. TH antibodies can therefore be used as markers for dopaminergic and noradrenergic neurons in a variety of applications including depression, schizophrenia, Parkinson’s disease, and drug abuse. TH antibodies can also be used to explore basic mechanisms of dopamine and norepinephrine signaling. The activity of TH is also regulated by phosphorylation. Phospho-specific antibodies for the phosphorylation sites on TH can be used to great effect in studying this regulation and in identifying the cells in which TH phosphorylation occurs.