Search results for "Structural Biology."

Negative staining and cryo-negative staining of macromolecules and viruses for TEM

2011

In this review we cover the technical background to negative staining of biomolecules and viruses, and then expand upon the different possibilities and limitations. Topics range from conventional air-dry negative staining of samples adsorbed to carbon support films, the variant termed the "negative staining-carbon film" technique and negative staining of samples spread across the holes of holey-carbon support films, to a consideration of dynamic/time-dependent negative staining. For each of these approaches examples of attainable data are given. The cryo-negative staining technique for the specimen preparation of frozen-hydrated/vitrified samples is also presented. A detailed protocol to su…

Keyhole limpet hemocyanin (KLH), II: Characteristic reassociation properties of purified KLH1 and KLH2.

1997

Subunits of the two types of keyhole limpet hemocyanin (KLH1 and KLH2), purified by gel filtration chromatography and preparative polyacrylamide gel electrophoresis from Immucothel, have been used for macromolecular reassociation studies. In-vitro reassociation has been achieved with a standardized system using a Tris-saline stabilizing buffer at pH 7.4 containing 100 mM calcium and magnesium chloride at 4 degrees C. The relatively slow progress of reassociation has been monitored and the varying oligomeric forms of KLH1 and KLH2 produced have been studied by transmission electron microscopy, using specimens negatively stained with 5% ammonium molybdate containing 1% trehalose. Specimens ha…

5-Methoxyuridine, a new modified constituent in tRNAs of Bacillaceae.

1976

Two-dimensional 1 H NMR spectra of ferricytochrome c 551 from Pseudomonas aeruginosa

1993

AbstractThe full assignment of 1H NMR signals of heme proton resonances of ferricytochrome c551 from Pseudomonas aeruginosa has been performed by means of 2D NMR experiments. This technique allows the complete and unequivocal assignment of all heme resonances, including methylene resonances of the propionic groups, directly implicated in the pH dependence of the redox properties of cytochrome c551.

Conformation and dynamics of the ligand shell of a water-soluble Au102 nanoparticle

2016

Inorganic nanoparticles, stabilized by a passivating layer of organic molecules, form a versatile class of nanostructured materials with potential applications in material chemistry, nanoscale physics, nanomedicine and structural biology. While the structure of the nanoparticle core is often known to atomic precision, gaining precise structural and dynamical information on the organic layer poses a major challenge. Here we report a full assignment of 1H and 13C NMR shifts to all ligands of a water-soluble, atomically precise, 102-atom gold nanoparticle stabilized by 44 para-mercaptobenzoic acid ligands in solution, by using a combination of multidimensional NMR methods, density functional t…

Synthesis of Tetrapeptide p‐nitrophenylanilides containing dehydroalanine and dehydrophenylalanine and their influence on cathepsin C activity

2001

Three dehydrotetrapeptides of rationally varying structure were prepared and tested as affectors of cathepsin C. These compounds appeared to be substrates of the enzyme, being equipotent with their classical counterparts. Thus, replacement of amino acid in a short peptide by corresponding dehydroamino acid does not prevent cathepsin C in recognizing dehydropeptide as its substrate. Copyright © 2001 European Peptide Society and John Wiley & Sons, Ltd.

Induction of the peroxisome proliferator activated receptor by fenofibrate in rat liver

1992

AbstractThe process of peroxisome proliferation in rodent liver by hypolipidemic compounds and related substances has recently been shown to be receptor-madiated. In the present study, we have examined the effect of oral administration of the strong peroxisome proliferator fenofibrate on the hepatic expression level of the peroxisome proliferator activated receptor (PPAR) in rats. Immunoblots of rat liver cytosols and nuclear extracs using antibodies raised against recombinant PPAR/β-galactosidase fusion proteins revealed a pronounced increase in the amount of PPAR protein in response to fenofibrate treatment. This induction could also be confirmed at the level or RNA by Northern blotting. …

Vitamin E activates CRABP-II gene expression in cultured human fibroblasts, role of protein kinase C

2004

The treatment of human fibroblasts with different tocopherols in the presence of retinol caused an increase in cytoplasmic retinoic acid binding protein II (CRABP-II) mRNA and protein. The possibility of an involvement of protein kinase C (PKC) in the response to tocopherols was supported by the results obtained with the PKC-specific inhibitors, calphostin C and bisindolylmaleimide I. The effect of alpha-tocopherol was prevented by okadaic acid, suggesting that a protein phosphatase is responsible for PKC dephosphorylation produced by the presence of tocopherols. The results shown support the hypothesis that phosphorylation/dephosphorylation of RXRalpha via PKC may be involved in the regula…

Noradrenaline release from permeabilized synaptosomes is inhibited by the light chain of tetanus toxin

1992

AbstractNoradrenaline release from rat brain cortical synaptosomes permeabilized with streptolysin O can be triggered by μM concentrations of free Ca2+. This process was inhibited within minutes by tetanus toxin and its isolated light chain, but not by its heavy chain. The data demonstrate that the effect of tetanus toxin on NA release from purified synaptosomes is caused by the intraterminal action of its light chain.

Effect of unbalanced diets on incorporation of δ-aminolevulinic acid into cytochrome P-450

1987

Abstract The in vivo syntheses of two liver microsomal cytochromes P-450 PB 3a , P-450 UT 50 [(1987) Eur. J. Biochem., submitted] ( M r 50 000, 52 000) have been estimated by measuring the specific activity 2 h after i.p. administration of δ-[ 3 H]aminolevulinic acid to male Sprague Dawley rats. The animals were fed either a standard rat chow (5% lard, 22% casein) or unbalanced diets (high lipid, 30% lard or low protein, 6% casein) with or without 50 ppm Phenoclor DP6. The high-lipid diet supported a more rapid body weight gain but had little impact on cytochrome P-450 content, expressed either per whole liver or per mg microsomal protein, and on the incorporation of the precursor into cyto…