Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A monoclonal antibody named TM60, which inhibited both thrombin- and ristocetin-induced platelet aggregations, was obtained by hybridoma technique. TM60 inhibited binding of von Willebrand factor to platelets under the presence of ristocetin. The subclass of TM60 was IgG2a. TM60 did not inhibit ADP-, collagen-A-23187-, arachidonic acid- and PAF-induced platelet aggregations, but inhibited polylysine-, polybrene- and cationized ferritin-induced platelet aggregations. ATP-release from platelets induced by thrombin was also inhibited by TM60. Immunoprecipitation and SDS-PAGE experiments demonstrated that TM60 recognized an epitope on GPIb whose molecular weight was 165,000 under non-reduced and 145,000 under reduced conditions.
 ...
PMID:Monoclonal antibody to glycoprotein Ib inhibits both thrombin- and ristocetin-induced platelet aggregations. 241 61

A method of affinity purification of a regulatory protein that binds specific RNA sequences is described. RNAs containing the regulatory sequences are transcribed in vitro from oligonucleotide templates, biotinylated, and incubated with unfractionated cytosol. Specific RNA-protein complexes are bound in solution to avidin, and the resulting complex is bound to biotin-agarose beads. The cytosolic binding protein is released from the RNA in high salt, and a second round of purification yields an essentially homogeneous protein. Using this method, we have identified the protein in human liver that binds iron-responsive RNA regulatory sequences. Iron-responsive elements (IREs) are RNA stem-loops present in the mRNAs encoding ferritin and the transferrin receptor. IREs form the basis for the translational regulation of ferritin gene expression and the regulation of transferrin receptor mRNA degradation rates. The IRE binding protein purified by this technique migrates as a 90-kDa polypeptide on SDS/PAGE. The interaction of the purified protein with IRE-containing RNAs can be detected by gel-mobility shift assays or by covalent crosslinking induced by UV irradiation.
 ...
PMID:The iron-responsive element binding protein: a method for the affinity purification of a regulatory RNA-binding protein. 247 19

The major ferritin species of mouse liver has been resolved by SDS-PAGE into two bands similar to the H and L subunits of rat liver ferritin with the L subunit predominating. Amino acid sequencing has confirmed the major, faster-migrating component as L chain. An additional, electrophoretically fast, minor ferritin was isolated from siderosome-containing subcellular fractions. In denaturing gels it gave a single 'F' subunit band of about 17 kDa, significantly smaller than the L and H subunits (about 20 and 21 kDa respectively). A small fragment isolated from the fast ferritin was sequenced. It corresponds to a 19-residue C-terminal peptide cleaved from L subunits in the assembled molecules. The F subunit must be derived from L subunits by loss of this peptide, and is not the expression product of a different gene. 'Fast' ferritins of siderotic mice and rats are thus analogous.
 ...
PMID:Ferritin subunits in livers of siderotic mice. 264 21

Crystalline accumulations of ferritin-like particles are present within the cytoplasma and the nucleus in midgut epithelial cells of the homopteran Philaenus spumarius. A structural study at the electron microscope level reveals that these particles have the morphological characteristics of the ferritin molecule: crystals have a face-centered cubic structure with a lattice parameter of 14 +/- 1 nm; negatively stained isolated particles have the appearance of ferritin; on rotary-shadowed particles 3 axes of symmetry are clearly seen; image processing performed on selected molecules demonstrates a 4-fold symmetry. A semiquantitative electron microprobe analysis effected on aggregates of microcrystals in thin sections reveals a high atomic ratio Fe/P. Analyzed by SDS-PAGE, the protein subunit has a molecular weight of 18,600. The amino acid composition of the protein bears the general characteristics of the ferritin molecule in terms of polar and nonpolar residues. But in terms of sequences, this protein displays a strong dissimilarity to rat liver ferritin as demonstrated with a common amino acid index test and with immunoelectrophoresis experiments.
 ...
PMID:Characterization of a ferritin isolated from the midgut epithelial cells of a homopteran insect, Philaenus spumarius L. 285 42

Microtubules (MT) and neurofilaments (NF) are linked by frequent crossbridges in situ. In order to answer the question of what makes these crossbridges, we performed the immunogold procedure on rat spinal cord motor neurons using an affinity-purified polyclonal antibody against rat brain MAP2 and gold-labeled anti-rabbit IgG goat IgG. A quick-freeze, deep-etch technique (QF-DE) in conjunction with decoration with anti-MAP2 antibody and ferritin-labeled second antibody was also used. In motor neuron dendrites crossbridges were clearly displayed between MTs and NFs by QF-DE. These crossbridges were revealed in thin sections as fuzzy filamentous structures between MT and NF. Gold particles studded the fuzzy structures associated with MT. Many such structures connected MTs to NFs. Furthermore, antibody complexes containing ferritin were localized on the crossbridges between MTs and NFs by the QF-DE study. In addition, we performed reconstitution experiments. We isolated 70 kDa (L) protein of neurofilaments from calf spinal cords and assembled L to form neurofilaments in vitro. MAP2 bound these neurofilaments according to both SDS-PAGE and QF-DE electron microscopy of the pellets of suspensions containing L proteins and MAP2. When we added tubulin to this suspension and polymerized it in the presence of taxol, neurofilaments were crosslinked with microtubules by MAP2 crossbridges. Hence, from these 2 approaches we concluded that MAP2 is a component of crossbridges between MTs and NFs in the neuronal cytoskeleton in vivo and in vitro.
 ...
PMID:MAP2 is a component of crossbridges between microtubules and neurofilaments in the neuronal cytoskeleton: quick-freeze, deep-etch immunoelectron microscopy and reconstitution studies. 304 69

Cell-surface IgM (antigen receptor) sediments with the membrane fraction following osmotic lysis and homogenization of cells of the human lymphoblastoid cell line WiL2. In nonreducing buffers, SDS PAGE analysis of membrane pellets demonstrates that "native" membrane IgM exists as a dimer. In contrast to osmotic lysis, lysis of cells with the nonionic detergent Triton X-100 releases approximately 90% of the membrane-bound IgM into the supernatant; approximately 10% of the IgM pellets with the cytoskeletal fraction on centrifugation. Ligand challenge with either mu-chain-specific antibodies or concanavalin A induces a change in the state of membrane IgM making it refractory to detergent extraction, such that 43% of the IgM pellets during centrifugation. This ligand-induced retention of IgM is significantly diminished by the microfilament-disrupting agent cytochalasin D, whereas pretreatment of cells with sodium azide or colchicine results in no significant change in the percentage of membrane IgM retained by Triton X-100 residues. These results indicate that retention of IgM involves an association with the cortical actin-based cytoskeleton. Investigation of the structural basis for ligand-induced Triton X-100 retention of membrane IgM by using ferritin-conjugated antibodies, myosin subfragment S1, and stereo-imaging electron microscopy has revealed linkages between ligand-receptor (antigen-IgM) complexes and elements of the cortical actin-based cytoskeleton.
 ...
PMID:Membrane IgM: interactions with the cortical cytoskeleton in the human lymphoblastoid cell line WiL2. 316 34

The major sialoglycoprotein of the human red cell membrane, glycophorin A, was isolated and examined by rotary shadowing and transmission electron microscopy. The glycophorin A molecule appeared as a cloud-like structure with a short, dense core within a large cloud. Mild acid hydrolysis in 0.05 M H2SO4, 80 degrees C for 1 hr reduced the size of the cloud significantly but left the dense core intact indicating that the original cloud represented the sialylated oligosaccharide chains of glycophorin A with the dense core being the polypeptide chain and its associated linkage proteins. Incubating glycophorin A with cationized ferritin (CF) revealed that the CF was bound only to the cloud, a finding that supports the view that the cloud is comprised of the sialylated oligosaccharide chains of the glycophorin A molecule. SDS-polyacrylamide gel electrophoresis revealed that our preparation of glycophorin A, as well as commercial preparations, consisted of monomers, dimers and oligomers of glycophorin A with trace amounts of the minor glycophorins and linkage proteins. Knowledge of the ultrastructure of this important integral protein will enable one to design studies to determine its functional role in the membrane.
 ...
PMID:Ultrastructure of a transmembrane glycoprotein, glycophorin A. 340 39

We generated a monoclonal anti-vimentin antibody, VIM-1, by mouse hybridoma technique, using an established myofibroblast line as a whole cell immunogen. The presence of vimentin polypeptides in the cultured myofibroblasts was confirmed by SDS-polyacrylamide gel electrophoresis and immunoblotting. By light microscopic immunocytochemistry, myofibroblasts in cultures as well as in frozen tissue sections showed a strong reaction with the anti-vimentin antibody, whereas these cells lacked either detectable desmin or cytokeratin. Our results support the fibroblastic origin of myofibroblasts. Immunoelectron microscopic study with ferritin-ABC technique demonstrated that VIM-1 reacted exclusively with 10-nm intermediate filaments, while other cellular structures revealed uniformly negative reaction against the antibody.
 ...
PMID:Intermediate filaments of myofibroblasts. Immunochemical and immunocytochemical analyses. 360 3

A minor electrophoretically fast component was found in ferritin from iron-loaded rat liver in addition to a major electrophoretically slow ferritin similar to that observed in control rats. The electrophoretically fast ferritin showed immunological identity with the slow component, but on electrophoresis in SDS it gave a peptide of 17.3 kDa, in contrast with the electrophoretically slow ferritin, which gave a major band corresponding to the L-subunit (20.7 kDa). Thus the electrophoretically fast ferritin resembles that reported by Massover [(1985) Biochim. Biophys. Acta 829, 377-386] in livers of mice with short-term parenteral iron overload. The electrophoretically fast ferritin had a lower iron content (2000 Fe atoms/molecule) than the electrophoretically slow ferritin (3000 Fe atoms/molecule). Removal and re-incorporation of iron was possible without effect on the electrophoretic mobility of either ferritin species. On subcellular fractionation the electrophoretically fast ferritin was enriched in pellet fractions and was the sole soluble ferritin isolated from iron-laden secondary lysosomes (siderosomes). The amount and relative proportion of the electrophoretically fast species increased with iron loading. Haemosiderin isolated from siderosomes was found to contain a peptide reactive to anti-ferritin serum and corresponding to the 17.3 kDa peptide of the electrophoretically fast ferritin species. Unlike the electrophoretically slow ferritin, the electrophoretically fast ferritin did not become significantly radioactive in a 1 h biosynthetic labelling experiment. We conclude that the minor ferritin is not, as has been suggested for mouse liver ferritin, 'a completely new species of smaller holoferritin that represents a shift in the ferritin phenotype' in response to siderosis, but a precursor of haemosiderin, in agreement with the proposal by Richter [(1984) Lab. Invest. 50, 26-35] concerning siderosomal ferritin.
 ...
PMID:Siderosomal ferritin. The missing link between ferritin and haemosiderin? 366 70

Conjugated-Schiff's-base-type fluorescence was measured in iron-depleted samples and chloroform extracts of human spleen haemosiderin. Incubation of ferritin with liposomes and ascorbate led to the formation of compounds with similar fluorescence properties. Analysis of protein subunits by SDS/polyacrylamide-gel electrophoresis confirmed that ferritin was damaged in incubations with ascorbate. Since previous studies have shown that intact ferritin is resistant to proteolytic degradation, it is suggested that haemosiderin may be a product of oxidative reactions involving ferritin and lipid.
 ...
PMID:Haemosiderin-like properties of free-radical-modified ferritin. 382 50


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