Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0272170 (SDS)
 50,377 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two distinct alpha-actinin-like proteins were detected in chicken lung extract by immunoblot analysis with monoclonal antibodies against alpha-actinin. The mobilities of these proteins on SDS-polyacrylamide gel electrophoresis are very close (approximately 100 kDa). On SDS-polyacrylamide gel electrophoresis in the presence of 6 M urea, however, one of the proteins migrates at 115 kDa and is clearly separated from the other protein (105 kDa). The 115-kDa protein was purified and shown to have at least three unique amino acid sequences which were not detected in other kinds of alpha-actinins: one locates at the extreme NH2-terminal region, and the others locate at the COOH-terminal half region. Immunoblot and proteolytic cleavage analyses revealed that the 115-kDa protein has structural divergence at the COOH-terminal region that includes Ca(2+)-binding EF-hand motifs. Falling-ball viscometric studies showed that although the 115-kDa protein-induced gelation of F-actin is sensitive to Ca2+, the gelation activity of the 115-kDa protein is much higher than that of Ca(2+)-insensitive gizzard alpha-actinin regardless of Ca2+. This indicates that the 115-kDa protein is distinct from other nonmuscle alpha-actinins by its Ca2+ sensitivity.
 ...
PMID:A novel nonmuscle alpha-actinin. Purification and characterization of chicken lung alpha-actinin. 133 89

Activation of various receptors by extracellular ligands induces an influx of Ca2+ through the plasma membrane, but its molecular mechanism remains elusive and seems variable in different cell types. In the present study, we utilized mAbs generated against the cerebellar type I inositol 1,4,5-trisphosphate (InsP3) receptor and performed immunocytochemical and immunochemical experiments to examine its localization in several non-neuronal cells. By immunogold electron microscopy of ultrathin frozen sections as well as permeabilized tissue specimens, we found that a mAb to the type I InsP3 receptor (mAb 4C11) labels the plasma membrane of the endothelium, smooth muscle cell and keratinocyte in vivo. Interestingly, the labeling with the antibody was confined to caveolae, smooth vesicular inpocketings of the plasma membrane. The reactive protein, with an M(r) of 240,000 by SDS-PAGE, could be biotinylated with a membrane-impermeable reagent, sulfo-NHS-biotin, in intact cultured endothelial cells, and recovered by streptavidin-agarose beads, which result further confirmed its presence on the cell surface. The present findings indicate that a protein structurally homologous to the type I InsP3 receptor is localized in the caveolar structure of the plasma membrane and might be involved in the Ca2+ influx.
 ...
PMID:Localization of inositol 1,4,5-trisphosphate receptor-like protein in plasmalemmal caveolae. 133 60

The sarcoplasmic Ca(2+)-ATPase was reduced with 300 mM 2-mercaptoethanol at elevated temperatures (40-45 degrees C) with a concomitant loss of ATPase activity. The reduction and inactivation of the Ca(2+)-ATPase proceeded rapidly in the absence of Ca2+. The Ca(2+)-ATPase was also inactivated with 2-mercaptoethanol in the presence of diluted SDS (0.4 mg/ml) even at 20 degrees C. In contrast to the (Na+, K+) ATPase, the inactivated Ca(2+)-ATPase in the presence of diluted SDS was sedimented by the centrifugation at 100,000 x g for 30 min.
 ...
PMID:Reduction and inactivation of the sarcoplasmic Ca(2+)-ATPase by 2-mercaptoethanol--contrast to the (Na+,K+) ATPase. 133 62

The two ryanodine-binding proteins (RyBPs) have been purified from sarcoplasmic reticulum of bullfrog skeletal muscle by Mono Q column chromatography following solubilization of SR by CHAPS and sucrose density gradient centrifugation. We conclude that the two RyBPs (alpha- and beta-RyBP) are isoforms on the basis (i) that each RyBP is distinguished by a specific polyclonal antibody and (ii) that distinct polypeptides are generated by limited tryptic digestion of the two RyBPs. Monomeric molecular weights for alpha- and beta-RyBP are estimated to be (690 +/- 10) and (570 +/- 10) kDa, respectively, as determined from mobilities on disc SDS-PAGE using the Weber-Osborn buffer system without 6 M urea, which gives an estimate of (590 +/- 10) kDa for RyBP of rabbit skeletal muscle. Similar determination in the presence of 6 M urea gave 630 kDa for alpha-RyBP and unchanged estimates for the other RyBPs. Both RyBPs show [3H]ryanodine-binding activities which are activated by Ca2+, AMPOPCP, and caffeine, and inhibited by ruthenium red, MgCl2, and procaine. beta-RyBP, however, has higher affinity for Ca2+. In the presence of Ca2+ and AMPOPCP, both RyBPs show single homogeneous binding sites for [3H]ryanodine with Kd = 2-5 nM. The values of Bmax for alpha- and beta-RyBP were 320-340 and 320-375 pmol/mg protein, respectively. These results are consistent with the conclusion that a homo-tetramer of each RyBP binds one ryanodine molecule, taking account of the estimated molecular weight.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Purification and characterization of two ryanodine-binding protein isoforms from sarcoplasmic reticulum of bullfrog skeletal muscle. 133 84

The distribution of ryanodine receptor calcium-release channels over the terminal cisternae (TC) membrane of skeletal muscle fibres was examined by using immunogold electron microscopy. Two monoclonal antibodies (5C3 and 8E2) that bound to monomers of the ryanodine receptor protein on Western blots of SDS-polyacrylamide gels were used to locate calcium-release channels in longitudinal sections of rat sternomastoid and diaphragm fibres. Up to 21% of 5C3 binding on TC membranes was extra-junctional, compared with 46% for 8E2. Binding of 8E2 to the fibres was less than half that of 5C3, possibly because of steric shielding of the 8E2 antigenic site at the junction. The distances between neighbouring particles in clusters was 20-40 nm, i.e. the distance between subunits of the ryanodine receptor or between neighbouring foot structures. We suggest that, during activation, extra-junctional ryanodine receptors may release Ca2+ directly into the myoplasm, rather than into the restricted space of the triad junction.
 ...
PMID:Extra-junctional ryanodine receptors in the terminal cisternae of mammalian skeletal muscle fibres. 134 23

Protease secreted into the culture medium by alkalophilic Thermoactinomyces sp. HS682 was purified to an electrophoretically homogeneous state through only two chromatographies using Butyl-Toyopearl 650M and SP-Toyopearl 650S columns. The purified enzyme has an apparent relative molecular mass of 25,000 according to gel filtration on a Sephadex G-75 column and SDS-PAGE and an isoelectric point above 11.0. Its proteolytic activity was inhibited by active-site inhibitors of serine protease, DFP and PMSF, and metal ions, Cu2+ and Hg2+. The enzyme was stable toward some detergents, sodium perborate, sodium triphosphate, sodium-n-dodecylbenzenesulfonate, and sodium dodecyl sulfate, at a concentration of 0.1% and pH 11.5 and 37 degrees C for 60 min. The optimum pH was pH 11.5-13.0 at 37 degrees C and the optimum temperature was 70 degrees C at pH 11.5. Calcium divalent cation raised the pH and heat stabilities of the enzyme. In the presence of 5 mM CaCl2, it showed maximum proteolytic activity at 80 degrees C and stability from pH 4-12.5 at 60 degrees C and below 75 degrees C at pH 11.5. The stabilization by Ca2+ was observed in secondary conformation deduced from the circular dichroic spectrum of the enzyme. The protease hydrolyzed the ester bond of benzoyl leucine ester well. The amino acid terminal sequence of the enzyme showed high homology with those of microbial serine protease, although alanine of the NH2-terminal amino acid was deleted.
 ...
PMID:Purification and characterization of a thermostable alkaline protease from alkalophilic Thermoactinomyces sp. HS682. 136 1

Nitric oxide (NO) synthase (EC 1.14.23) was purified to homogeneity from bovine cerebrum. The molecular weight of NO synthase was estimated to be 150 kDa by both SDS/PAGE and gel filtration at high salt concentration. For activity, the enzyme required NADPH, Ca2+, calmodulin and tetrahydrobiopterin as cofactors. Rabbit polyclonal antibody to bovine brain NO synthase reacted with 150 kDa NO synthase in various bovine and rat organs, including the brain, pituitary and adrenal glands, but not with that in stimulated macrophages, indicating that there are at least two immunologically distinct NO synthases.
 ...
PMID:Purification of nitric oxide synthase from bovine brain: immunological characterization and tissue distribution. 137 19

We investigated the possible role of tyrosine phosphorylation in the activation process of mast cells by cross-linking of cell-bound IgE antibodies. Bone marrow-derived mouse mast cells (BMMC) were sensitized with mouse IgE antiDNP mAb and then challenged with multivalent Ag DNP conjugates of human serum albumin. Analysis of phosphotyrosine-containing proteins in their lysates by SDS-PAGE and immunoblotting revealed that cross-linking of cell-bound IgE antibodies induced a marked increase in tyrosine phosphorylation of several proteins. To obtain direct evidence for activation of protein-tyrosine kinases (PTK), phosphotyrosine-containing proteins in lysates of mast cells were affinity purified, and kinase activity of the immunoprecipitates was assessed by an in vitro kinase assay. The results clearly showed activation of PTK upon cross-linking of Fc epsilon RI. Activation of PTK was not detected by the same assay when the sensitized BMMC were challenged with monovalent DNP-lysine. Treatment of sensitized BMMC with either Ca2+ ionophore or PMA failed to induce the activation of PTK. A representative IgE-independent secretagogue, thrombin, induced histamine release from BMMC but failed to induce activation of PTK. The results excluded the possibility that PTK activation is the consequence of an increase in intracellular Ca2+ or activation of protein kinase C. Addition of genistein, a PTK inhibitor, to sensitized BMMC before Ag challenge inhibited not only Ag-induced PTK activation, but also inositol 1,4,5-trisphosphate production, and histamine release in a similar dose-response relationship. Other PTK inhibitors, such as lavendustin A and tyrphostin RG50864, also inhibited the Ag-induced activation of PTK and histamine release. The results collectively suggest that activation of PTK is an early event upstream of the activation of phospholipase C, and is involved in transduction of IgE-dependent triggering signals to mediator release.
 ...
PMID:Tyrosine phosphorylation is required for mast cell activation by Fc epsilon RI cross-linking. 137 48

An endotoxin-induced form of nitric oxide synthase (EC 1.14.23) was purified to homogeneity from rat liver by sequential anion-exchange chromatography and affinity chromatography using 2',5'-ADP-Sepharose. The enzyme has a subunit molecular mass of 135 kDa as determined by SDS/PAGE, a maximum specific activity of 462 nmol of citrulline formed from arginine per min per mg, and a Km for arginine of 11 microM. The enzyme was strongly stimulated by the addition of calmodulin with an EC50 of 2 nM, but removal of free calcium from the assay medium only reduced activity by 15%. Calmodulin inhibitors significantly reduced the enzyme activity. Tetrahydrobiopterin, FAD, and FMN were all required for full enzyme activity. This form of endotoxin-induced nitric oxide synthase from liver differs from the inducible enzyme found in macrophages and is unusual in that it is stimulated by calmodulin with little dependence on the calcium ion concentration.
 ...
PMID:Purification of a distinctive form of endotoxin-induced nitric oxide synthase from rat liver. 137 17

Nitric oxide synthase [EC 1.14.23] from the particulate fraction of rat cerebella was purified and characterized. The homogenate of rat cerebella was centrifuged to obtain a pellet, which was washed and incubated with Triton X-100 containing buffer. The enzyme activity appeared in the 100,000 x g supernatant after incubation with the detergent. The solubilized enzyme was then purified by sequential affinity chromatography using adenosine 2',5'-diphosphate agarose and calmodulin Sepharose 4B, which gave a product that migrated as a single protein band on SDS/PAGE with a molecular mass of about 150 kDa. The purified enzyme exhibited an absolute requirement for FAD, in addition to NADPH and Ca2+/calmodulin. Thus, there is an insoluble nitric oxide synthase in rat cerebellum that has similar characteristics to the soluble type.
 ...
PMID:Purification of insoluble nitric oxide synthase from rat cerebellum. 137 22


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>