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)

Ependymin, a glycoprotein of the brain ECF, has been implicated in the neurochemistry of memory and neuronal regeneration. Three behavioral experiments (swimming with a float, avoidance conditioning, and classical conditioning) in the goldfish and one in the mouse (T-maze learning) indicate that ependymin has a role in the synaptic changes that take place in the consolidation step of memory formation and the activity-dependent phase of sharpening of goldfish retinotectal connections during neuronal regeneration. The ECF concentration of the protein was found to decrease after the goldfish learned to associate a light stimulus (CS) with the subsequent arrival of a shock (US): paired CS-US gave changes whereas an unpaired presentation of CS-US gave no changes relative to the unstimulated controls. Ependymin is present in ECF as a mixture of three disulfide-linked dimers of two acidic (alpha and beta) polypeptide chains (37 kDa and 31 kDa). Upon removal of its N-linked glycan fragment by N-glycosidase F, the beta chain yields gamma-ependymin (26 kDa). Determinations of the amino acid sequence of gamma-ependymin indicate that it is a unique protein with no long sequence homologies to any known polypeptide. There are, however, small segments (5-7 amino acids long) with homologies to fibronectin, laminin, and tubulin. Ependymin has the capacity to polymerize into FIP (after activation by phosphorylation) in response to events that deplete ECF calcium. FIP is insoluble in 2% SDS in 6 M urea, 10 mM Ca2+Ac2, 100% acetic acid, chloroform/methanol (2/1), saturated KCNS, and even 100% trifluoroacetic acid. FIP was found to be present in goldfish brain and to be formed as a labeled product in vivo. Ependymin's FIP-forming property was used to propose a molecular hypothesis for generating synaptic changes in response to local extracellular depletions of calcium at sites of "associating inputs." The model assumes that, following NMDA receptor stimulation, the translocated PKC that is generated activates extracellular ependymin by converting it to its phosphorylated form using presynaptically released ATP. The hypothesis was tested in studies of LTP of rat hippocampal slices at CA1. After LTP, new sites that stained with antisera to ependymin, visible at 100x, were obtained in its potentiated radiatum in the CA1 region but not in the unpotentiated CA3. Electron microscopic studies showed that the horseradish peroxidase reaction product obtained was localized at synaptic clefts and postsynaptic regions. The results suggest that FIP may be formed at extracellular and postsynaptic loci where multiple associating inputs interact at CA1.
 ...
PMID:Ependymin, a brain extracellular glycoprotein, and CNS plasticity. 183 64

A novel peroxidase that catalyses the dimerization of ferulic acid or caffeic acid via oxidative coupling and formation of beta beta'-linkage to the lignan-type compounds 8,8'-bis(caffeic acid) or 8,8'-bis(ferulic acid) respectively was purified from the leaves of Bupleurum salicifolium. The enzyme, for which the name caffeate peroxidase is proposed, was purified 2700-fold. It is a glycoprotein and has an Mr of 38,000 as determined by gel filtration and SDS/PAGE. The Km values for ferulic acid and caffeic acid were 0.24 mM and for H2O2 0.04 mM with caffeic acid and 0.48 mM with ferulic acid. The purified peroxidase does not exhibit activity on other phenylpropanoids tested and has no detectable phenol oxidase or NADPH oxidase activity. The caffeate peroxidase could be involved in the biosynthesis of lignans.
 ...
PMID:Purification of a new peroxidase catalysing the formation of lignan-type compounds. 184 25

We have used successive density gradient centrifugation with vesicles prepared from a human hepatoma Hep G2 post nuclear supernatant to obtain a highly enriched preparation of early endosomes. A monoclonal antibody (8E4) raised against this early endosome preparation recognizes a single polypeptide highly enriched in light vesicle membranes. The antigen has a molecular weight of 195 kDa by SDS-PAGE in the presence or absence of a reducing agent. Western blot analysis shows that the 8E4 antigen is detectable only in light vesicle membranes and not among heavy membranes, whole cytosol, or nuclear pellet proteins. The 8E4 antigen appears to be an integral membrane protein as it is precipitated by Triton X-114. The distribution of the 8E4 antigen in a Nycodenz density gradient fractionation of light vesicle membranes is identical to the distribution of 125I-ASOR-labeled early endosomes but distinct from the distribution of the plasma membrane enzyme, alkaline phosphodiesterase. In addition, incubation of cells with a horseradish peroxidase-transferrin conjugate followed by 3,3'-diaminobenzidine cytochemistry specifically quenches 8E4 antigen detection by protein dot blot analysis. These data strongly suggest that the 8E4 antigen is an integral membrane protein primarily located in endocytic vesicles.
 ...
PMID:Identification of an endosome-specific antigen. 184 26

The cDNA encoding Mn peroxidase isozyme H4 from Phanerochaete chrysosporium was recombined into a baculovirus and heterologously expressed in Sf9 cells. The recombinant Mn peroxidase has the same molecular weight as the native enzyme as determined by SDS-PAGE and cross-reacts with a Mn peroxidase-specific antibody. The recombinant enzyme has a slightly lower pI than the native fungal isozyme H4 indicating some differences in post-translational modification. Phenol red, guaiacol, and vanillylacetone, substrates of the native Mn peroxidase, are oxidized by the recombinant enzyme. All of the activities are dependent on both Mn (II) and H2O2.
 ...
PMID:Heterologous expression of active manganese peroxidase from Phanerochaete chrysosporium using the baculovirus expression system. 189 10

1. The biochemical properties of bovine, goat and sheep lactoferrin were compared. Molecular weights of the three lactoferrins were estimated to be 78,000 to 80,000 as determined by SDS-PAGE. By IEF, microheterogeneity was observed for all of them. 2. Partial antigenic identity was observed between bovine lactoferrin and goat or sheep lactoferrin by immunodiffusion method. 3. CD spectra at the u.v. region of the three lactoferrins suggested their similar secondary and tertiary structural profiles. 4. Reactivities with peroxidase-conjugated lectins showed that the carbohydrate compositions of the three ruminants' lactoferrin were the same but not identical with that of human lactoferrin.
 ...
PMID:Comparison of bovine, sheep and goat milk lactoferrins in their electrophoretic behavior, conformation, immunochemical properties and lectin reactivity. 190 66

Tear samples were collected from 46 healthy volunteers evenly distributed according to sex and age (mean age 43.5 years). Samples were denatured in a Tris-HCl sample buffer containing 2-mercaptoethanol and SDS, and applied to a gradient SDS-polyacrylamide gel for electrophoresis. The proteinaceous material was transferred to nitrocellulose by a semi-dry blotting technique, and the glycoprotein content subsequently visualized by incubation with four lectins (WGA, PHA, PSA and SBA) and staining with avidin horseradish-peroxidase. Glycoprotein bands were generally found to be significantly less frequent in persons under the age of 30 years. Apart from this the technique gave a uniform picture of the glycoprotein profile, with only modest differences according to age and/or sex. The technique may therefore be suitable for the detection of differences in the glycoprotein composition indicative of disease.
 ...
PMID:The normal human tear glycoprotein profile detected with lectin probes. 193 80

Polyclonal antisera to a SDS-denatured and partially renatured rat luteal 90 K LH/CG receptor were raised in rabbits, characterized, and their applicability for immunohistochemical location of the receptor examined. The LH/CG receptor was purified by hCG-affinity chromatography and subjected either to a preparative SDS-PAGE or Western blotting. Gel slices containing the SDS-denatured or nitrocellulose strips containing the renatured 90 K LH/CG receptor were used for immunization. The antisera, termed ARS-2 and ARS-3, respectively, possessed similar antibody titres. Both antisera were able to recognize the native, SDS-denatured, and SDS-denatured and reduced forms of the LH/CG receptor on dot blots, but only ARS-3 contained antibodies to the hormone binding site or a region near to it, as it was able to inhibit the hCG binding to the membrane-bound LH/CG receptor in a dilution-dependent manner. Both antisera recognized the receptor-hCG complex, but ARS-2 stained the complex with about 50% less intensity than the free receptor. ARS-3 located the LH/CG receptor distinctly on the luteal cell surfaces in immunohistochemical staining with peroxidase antiperoxidase complex method, but ARS-2, although it possessed similar antibody titre, revealed negligible staining. Thus, the antisera readily recognize the native receptor, but differ in their capability for inhibiting hormone binding. Only ARS-3, produced against the renatured receptor, contains sufficient amounts of antibodies capable of recognizing free and occupied receptors in immunohistochemistry.
 ...
PMID:Two polyclonal antisera to rat luteal LH/CG receptor with different ligand binding inhibition and immunohistochemical receptor detection capabilities. 195 Mar 43

An enzyme-linked immunosorbent assay (ELISA) has been developed to detect antibodies against surface components of rat islet and spleen lymphocytes. Live islet tumor RIN5 AH cells expressing characteristic ganglioside target antigens or rat spleen cells were immobilized onto wells of microtiter polystyrene plates precoated with poly-l-lysine and then incubated with test or normal rat sera. Cell surface-bound antibodies were quantitated after reaction with horseradish peroxidase-conjugated rabbit anti-rat Ig. With this assay, 46% (6/13) of sera from diabetes-prone BB rats and 100% (8/8) of sera from rats treated with complete Freund's adjuvant/streptozotocin (CFA/STZ) prior to immunization with RIN cells had islet cell surface antibodies: 54% (7/13) and 75% (6/8), respectively, were positive for lymphocyte antibodies (defined as the HRP anti-rat Ig binding exceeding the mean + 2SD of control group values). SDS polyacrylamide gel electrophoresis followed by immunoblotting analysis suggested that the islet cell antibodies in sera from the BB and CFA/STZ rats recognized RIN-cell components that were different in their molecular weights. These antigens were not detectable on spleen cells indicating that the ELISA described can be used to quantitate levels of islet cell specific antibodies which possibly reflect beta cell damage with progression to islet degeneration in the rat.
 ...
PMID:Detection of antibodies to islet cell and splenic lymphocytes in diabetes-prone BB and adjuvant-streptozotocin treated Lewis rats by ELISA and immunoblot analysis. 209

Prostaglandin endoperoxide synthase (PES, EC 1.14.99.1) catalyse the conversion of arachidonic acid into prostaglandin H2. The enzyme is a 140 kDa homodimer which contains both a cyclo-oxygenase activity (converting arachidonate into prostaglandin G2) and peroxidase activity (reducing prostaglandin G2 to H2). PES undergoes rapid self-inactivation during oxygenation of arachidonate to prostaglandin H2 in vitro. The previously reported cDNA-derived amino acid sequence indicates numerous sites for trypsin or thrombin cleavage. Most of these sites must be inaccessible, since these enzymes cleave only at Arg253. The enzyme appears to be a self-adherent and highly folded molecule, since after cleavage it retains its functional assembly and its homodimer size of 140 kDa, as well as its overall enzymic activity. Only under denaturing conditions (e.g. SDS/PAGE) can the proteolytic peptides be demonstrated: a 38 kDa C-terminal fragment containing the aspirin-derived-acetyl-binding ability, and a 33 kDa N-terminal fragment. In the present studies we investigated whether the two enzymic activities of PES can be differentially manipulated by proteolytic cleavage or by substrate (arachidonate) self-inactivation. The results indicated that, during arachidonate oxygenation by PES, the cyclooxygenase activity is selectively inactivated, whereas the peroxidase activity is essentially retained. By contrast, thrombin or trypsin cleavage of pure PES or microsomal PES (to yield the 38 and 33 kDa peptide fragments) inactivated the peroxidase, but not the cyclo-oxygenase. Taken together, these results suggest the presence of separate cyclo-oxygenase and peroxidase structural domains on the enzyme.
 ...
PMID:Differential modification of cyclo-oxygenase and peroxidase activities of prostaglandin endoperoxidase synthase by proteolytic digestion and hydroperoxides. 211 18

Monoclonal anti-fluorescein isothiocyanate (FITC) antibody cross-reacts with 7-hydroxy coumarin derivatives conjugated to BSA. This property permitted the affinity purification of monoclonal anti-FITC antibodies from ascitic fluid using an-immunosorbent consisting of a 7-hydroxy coumarin derivative linked to Sepharose 4B. Ascitic fluid was applied to the immunosorbent column and, after washing, the bound antibody was eluted under extremely mild conditions using 3 M MgCl2. Antibody eluted in this manner was greater than 96% pure as assessed by SDS-PAGE. A polyclonal sheep anti-FITC antibody was also purified from serum on the same immunosorbent to greater than 94% purity. This simple and rapid method for the purification of anti-FITC antibodies will find applications in both immunodiagnostic procedures and in studies of hapten-antibody interactions. The affinity constant of the purified monoclonal anti-FITC antibody conjugated to horseradish peroxidase was assessed by ELISA and was found to be 1.5 x 19(9) M-1.
 ...
PMID:A single-step method for the purification of anti-FITC antibodies by use of a coumarin immunosorbent. 212 Mar 48


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