Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The distribution of mass within the vertebrate skeletal thick filament has been determined by scanning transmission electron microscopy. Thick and thin filaments from fresh rabbit muscle were mixed with tobacco mosaic virus (TMV), fixed with formaldehyde, dried onto thin carbon films and viewed in a computer-linked microscope. Electron scattering data from both TMV and thick filaments were analysed with reference to the long axis of the particles so that the distribution of mass within the particles could be determined. While TMV appeared to be a uniform rod at the resolution employed (4.3 nm), the thick filament was clearly differentiated along its length. M-line remnants at the centre of the filament were flanked by regions of low mass per unit length, corresponding to the bare zone of the filament, and then by the more massive cross-bridge regions. The mass per unit length was approximately constant through most of the cross-bridge zone and declined at the filament tips, in a manner consistent with a constant number of myosin molecules per 14.3 nm interval (crown) throughout the cross-bridge zone. Fourier analysis of the data failed to detect the expected 43 nm periodicity of C-protein. The total mass of the thick filament was 184 Mdalton (s.e.m., 1.6 X 10(6); n = 70). The mass of adhering M-line proteins was highly variable but, on average, was about 4 Mdalton. The total mass of the filament and the mass distribution in the cross-bridge zone are consistent with three myosin molecules per crown.
J Mol Biol 1986 May 05
PMID:Distribution of mass within native thick filaments of vertebrate skeletal muscle. 378 72

Initial aggregates formed in collagen self-assembly were visualized by electron microscopy, using formaldehyde to fix the state of aggregation at various points in the turbidimetric lag phase. Measurements of the length distributions of monomers and small oligomers show that the first-formed aggregates are dimeric, with the most prevalent dimer having a maximal (approximately equal to 4D; D = 67 nm) stagger between constituent molecules.
J Mol Biol 1986 Jul 05
PMID:Collagen self-assembly in vitro: electron microscopy of initial aggregates formed during the lag phase. 378 94

The v-abl transforming protein P160v-abl and the P210c-abl gene product of the translocated c-abl gene in Philadelphia chromosome-positive chronic myelogenous leukemia cells have tyrosine-specific protein kinase activity. Under similar assay conditions the normal c-abl gene products, murine P150c-abl and human P145c-abl, lacked detectable kinase activity. Reaction conditions were modified to identify conditions which would permit the detection of c-abl tyrosine kinase activity. It was found that the Formalin-fixed Staphylococcus aureus formerly used for immunoprecipitation inhibits in vitro abl kinase activity. In addition, the sodium dodecyl sulfate and deoxycholate detergents formerly used in the cell lysis buffer were found to decrease recovered abl kinase activity. The discovery of assay conditions for c-abl kinase activity now makes it possible to compare P150c-abl and P145c-abl kinase activity with the altered abl proteins P160v-abl and P210c-abl. Although all of the abl proteins have in vitro tyrosine kinase activity, they differ in the way they utilize themselves as substrates in vitro. Comparison of in vitro and in vivo tyrosine phosphorylation sites of the abl proteins suggests that they function differently in vivo. The development of c-abl kinase assay conditions should be useful in elucidating c-abl function.
Mol Cell Biol 1985 Nov
PMID:Detection of c-abl tyrosine kinase activity in vitro permits direct comparison of normal and altered abl gene products. 387 12

Protein A-containing formaldehyde-fixed S. aureus (strain Cowan) was incubated with an antiviral serum or with a monospecific serum against NP protein, washed, and used as immunosorbent in order to isolate viral ribonucleoproteins (nucleocapsids) containing intact viral RNA from the extracts of influenza virus infected [3H]-uridine-labelled cells.
Mol Gen Mikrobiol Virusol 1985 Nov
PMID:[The use of immunosorption for the analysis of influenza virus RNA in intracellular viral ribonucleoproteins]. 391 13

Two products of modified adenine have been isolated from reaction of adenine with a mixture of formaldehyde and methylamine; their structures have been demonstrated by UV, 1H NMR and mass spectra data. The formal scheme of reaction can be described as simultaneous or sequential cycloaddition of dimethylol derivatives of methylamine to two reaction's positions of the adenine residue. This results in the formation of a new partly or completely hydrogenated six-membered 1,3,5-triazine cycle which has the atoms of adenine nitrogen in its 1,3-positions and nitrogen of methylamine in 5-position. This is used as a model for discussing the peculiarities of DNA-formaldehyde interaction in the presence of amine.
Mol Biol (Mosk)
PMID:[Interaction of formaldehyde with nucleic acids and their structural components in the presence of amines. II. Structure of adenine derivatives formed in the reaction with formaldehyde and primary amine]. 403 42

The binding of isolated high mobility group proteins HMG (1 + 2) with nucleosomes was studied using gel electrophoresis. The interaction of HMG (1 + 2) with mononucleosomes could be detected as a new discrete electrophoretic band with a decreased mobility only after cross-linking of HMG (1 + 2)-nucleosome complex by formaldehyde. Approximately two molecules of the large HMG proteins were bound per nucleosomal particle of a DNA length of approximately 185 base pairs, lacking histones H1 and H5. Using the same techniques, no binding was observed with core particles of a DNA length of approximately 145 base pairs.
Mol Biol Rep 1985 Oct
PMID:Interaction of high mobility group proteins HMG 1 and HMG 2 with nucleosomes studied by gel electrophoresis. 406 7

Contact-site cross-linking agents comprise a heterogeneous grouping of cross-linkers which share the common property of being able to cross-link only very closely juxtaposed residues in macromolecular complexes. We have defined contact-site cross-linking arbitrarily as the covalent joining of residues such that they are constrained to a distance which is equivalent to or less than their closest possible steric approach prior to becoming linked (1). We recognize two classes of contact-site cross-linkers, bridge type and zero-length type. The former, such as formaldehyde, become incorporated during cross-linking as one-atom bridges. The latter, such as the carbodiimides, operate as condensing agents with the result that the cross-linked residues become interjoined directly. Contact-site cross-linkers have been used in several ways as specific probes of both the static and dynamic aspects of macromolecular structure. They can yield precise structural information about macromolecular contacts when actual sites of cross-linking are determined by peptide or nucleotide mapping techniques. In this way exact contacts between histones in the nucleosome, between protein and RNA in the ribosome, and between RNA polymerase and DNA have been determined. Contact-site cross-linkers have also been used to probe the perturbation of contacts following macromolecular conformational changes. Certain histone-histone 'cross-linkable' sites are rendered unreactive after induction of chromatin conformational changes thus serving to localize sites of perturbation.
Mol Cell Biochem 1981 Jan 20
PMID:Contact-site cross-linking agents. 611 63

The rat monoclonal antibody YC5/45 has been shown to react specifically with serotonin containing neurones, and does not detect dopamine containing sites. On the other hand the monoclonal antibody recognizes dopamine, since it is capable of inhibiting the binding of 3H-YC5/45 to sheep red blood cells coated with serotonin albumin conjugate, or the direct agglutination of the same cells by the monoclonal antibody. Tryptamine and 5-methoxytryptamine are even better inhibitors, while derivatives with a modified-CH2-CH2-NH2 group are inactive. Treatment of the active compounds with paraformaldehyde increases their efficiency dramatically. The binding of antibody was also tested by cross linking with paraformaldehyde: dopamine, serotonin, tryptamine, 5-methoxytryptamine etc., to serum albumin. Only the serotonin derivative was active. The result shows that the discrimination specificity observed in immunohistochemistry is due to the paraformaldehyde fixation. It is concluded that for histochemical detection of serotonin by YC5/45, two reactive sites are necessary. The -CH2-CH2-NH2 group is probably modified by formaldehyde to produce a cyclic derivative to form the antibody recognition site. A different formaldehyde reactive site is required for cross linking to the tissue and this is provided by the presence of the 5-OH of serotonin which is absent in the others.
Mol Immunol 1983 Jan
PMID:The discrepancy between the cross-reactivity of a monoclonal antibody to serotonin and its immunohistochemical specificity. 619 77

With the application of radioactive formaldehyde and glycine the ability of aminomethylol compounds to combine with S1 nuclease treated DNA at 25 degrees and pH 5.8--7.4 has been shown. The reaction leads to modification of 22--26% of base pairs without changes of the DNA UV-absorption spectrum. Besides that the flexibility coefficient, the kinetics of despiralization under the action of formaldehyde and the stability of DNA molecule towards the S1 nuclease action permit to conclude that modification does not cause DNA despiralization. In experiments with the use of synthetic double-stranded polynucleotides poly(dA) times poly(dT), poly(rC) times poly(rl), poly(rG) times poly(dC) and poly(dC-dG) times poly(dC-dG) it has been shown that binding of methylol compounds to nucleic acids is due to reaction with guanine residues. Methylol derivatives of glycine reacts with guanine residues of double-stranded DNA only 10 times slower than with the monomer--deoxyguanosine-5'-phosphate. The studied reaction is reversible and the half-period of modified DNA reduction is found to be 5 hours at 25 degrees and pH 6.5. The rate constants of forward and reverse reactions and equilibrium constants of the reaction between methylolglycine and native DNA were determined.
Mol Biol (Mosk)
PMID:[Modification of guanine residues in double-stranded DNA by aminomethylol compounds without denaturation of nucleic acid]. 627 61

The effects of phenytoin (DPH) on folate metabolism have been studied in female Swiss Webster mice. Doses of DPH which produce steady-state plasma levels of DPH in the therapeutic range of 10-20 micrograms/ml were found to decrease plasma folate levels. In addition, the in vivo oxidation rate of [14C] formate and [2-14C] histidine to 14CO2 was increased. The increased metabolic rates were accompanied by a decrease in the hepatic activity of N5, N10-methylenetetrahydrofolate (5, 10-CH2-H4folate) reductase. N5-methyltetrahydrofolate-homocysteine transmethylase (methionine synthase); EC 2.1.1.13) activity in the liver was unchanged. The distribution of folates in the liver was determined by high-pressure liquid chromatography (HPLC) and it was found that the concentration of tetrahydrofolate (H4folate) was increased in DPH-treated mice whereas the concentration of N5-methyltetrahydrofolate was decreased. These effects were observed in mice treated with DPH for 4 days, but not in mice given a single DPH injection 24 hr previously. Decreased activity of hepatic 5, 10-CH2-H4folate reductase is postulated to account for the other effects which were observed. Decreased activity presumably results in increased tissue concentrations of 5, 10-CH2-H4folate, which is in equilibrium with its dissociation products, H4folate and formaldehyde. Increased concentrations of H4folate lead to increases in the oxidation rate of formate and histidine. These effects on folate metabolism may have important implications in the pharmacological and toxicological effects of DPH.
Mol Pharmacol 1984 May
PMID:Decreased hepatic 5, 10-methylenetetrahydrofolate reductase activity in mice after chronic phenytoin treatment. 637 25


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