Search results for " (OCT)"
showing 10 items of 284 documents
Comparative Study of the Mechanical Unfolding Pathways of α- and β-Peptides
2015
Using molecular simulations, we analyze the unfolding pathways of various peptides. We compare the mechanical unfolding of a β-alanine's octamer (β-HAla8) and an α-alanine's decamer (α-Ala10). Using force-probe molecular-dynamics simulations, to induce unfolding, we show that the 3(14)-helix formed by β-HAla8 is mechanically more stable than the α-helix formed by α-Ala10, although both structures are stabilized by six hydrogen bonds. Additionally, computations of the potential of mean force validate this result and show that also the thermal stability of the 3(14)-helix is higher. It is demonstrated that β-HAla8 unfolds in a two-step fashion with a stable intermediate. This is contrasted wi…
Application dans le temps de la convention de La Haye du 19 octobre 1996
2014
International audience; Civ. 1re, 20 mars 2013, 2 arrêts, n° 11-24.388 et 11-28.025, D. 2013. 837 ; AJ fam. 2013. 298, obs. A. Boiché
Oxidation of diclofenac in the presence of iron(II) octacarboxyphthalocyanine
2021
Abstract This paper presents the results of the research on the influence of catalytic activity of iron(II) octacarboxyphthalocyanines (FePcOC) on the transformation of diclofenac (DCF) which is the most popular anti-inflammatory analgesic. Diclofenac poses a serious threat to the natural environment. The paper demonstrates that diclofenac, in the presence a monomeric form of iron octacarboxyphthalocyanine and hydroxyl radicals (HO•) (from H2O2), undergoes a transformation into diclofenac-2,5-iminoquinone (DCF-2,5-IQ), causing distinct changes in the UV–Vis absorption spectrum. In the presence of iron octacarboxyphthalocyanine and H2O2, the previously colourless diclofenac solution becomes …
Interaction between N-terminal domain of H4 and DNA is regulated by the acetylation degree.
1998
Abstract To study whether the acetylation of one or more of the four acetylatable lysines of histone H4 affects its binding to DNA, we have designed a protection experiment with a model system consisting in phage lambda DNA as substrate, Stu I as restriction endonuclease and histone H4 with different degrees of acetylation as the protective agent. It can be deduced from the experimental data that the protection afforded by the histone is not dependent on the number of positive charges lost by acetylation. Thus, non-acetylated H4 and mono-acetylated H4 cause similar protection, while di-acetylation of the histone seems to be the crucial step in significantly weakening the interaction between…
Enzymes involved in the dynamic equilibrium of core histone acetylation ofPhysarum polycephalum
1992
DEAE-Scpharose chromatography of extracts from plasmodia of the myxomyccte PI~.~suru~~t ,~/.~crpl~~ho~~ revealed the presence of multiple histone acetyltransferases and histonc deacctylascs. A cyloplasmic histonc acctyltransferase B, specific for histonc H4, and two nuclear acetyltransferases Al and A2 were identilied; Al acetylates all core hislones with a preference for l-13 and H2A. whereas A2 is specific for H3 and also slightly for H2B. Two hislone deacetylases. HDI and HD2, could be discriminated. They differ with respect to subslralc speciliciiy and pH dependence. For the first time the substrate specificity of histonc deacetylascs was determined using HPLC-purilicd individual core h…
Gcn5p is involved in the acetylation of histone H3 in nucleosomes.
1997
Abstract Enzymatic extracts from a gcn5 mutant and wild-type strains of Saccharomyces cerevisiae were chromatographically fractionated and the histone acetyltransferase activities compared. When free histones were used as substrate, extracts from wild-type cells showed two peaks of activity on histone H3 but extracts from gcn5 mutant cells showed only one. With nucleosomes as substrate, the histone acetyltransferase activities present in extracts from the gcn5 mutant strain were not able to modify H3 whereas wild-type cell extracts acetylated intensely this histone. The activity that acetylated nucleosome-bound H3 behaved as a 170-kDa complex. We suggest that Gcn5p represents a catalytic su…
Histone Code and Higher-Order Chromatin Folding: A Hypothesis
2016
AbstractHistone modifications alone or in combination are thought to modulate chromatin structure and function; a concept termed histone code. By combining evidence from several studies, we investigated if the histone code can play a role in higher-order folding of chromatin. Firstly using genomic data, we analyzed associations between histone modifications at the nucleosome level. We could dissect the composition of individual nucleosomes into five predicted clusters of histone modifications. Secondly, by assembling the raw reads of histone modifications at various length scales, we noticed that the histone mark relationships that exist at nucleosome level tend to be maintained at the high…
OCT e GDx VCC : hardware e software di analisi
2009
Vengono comparati i programmi con le specifiche metodiche di esami dei 2 strumenti per la dia gnosi precoce del glaucoma.
Histone H3 Lysine 4 Mono-methylation does not Require Ubiquitination of Histone H2B
2005
The yeast Set1-complex catalyzes histone H3 lysine 4 (H3K4) methylation. Using N-terminal Edman sequencing, we determined that 50% of H3K4 is methylated and consists of roughly equal amounts of mono, di and tri-methylated H3K4. We further show that loss of either Paf1 of the Paf1 elongation complex, or ubiquitination of histone H2B, has only a modest effect on bulk histone mono-methylation at H3K4. Despite the fact that Set1 recruitment decreases in paf1delta cells, loss of Paf1 results in an increase of H3K4 mono-methylation at the 5' coding region of active genes, suggesting a Paf1-independent targeting of Set1. In contrast to Paf1 inactivation, deleting RTF1 affects H3K4 mono-methylation…
[(1,4,8,11-Tetraazacyclotetradeca-1,4,8,11-tetrayl)tetraacetamide-kappa6N1,N4,N8,N11,O1,O8]copper(II) sulfate 4.5-hydrate.
2002
The crystal structure of the title copper(II) complex, [Cu(C(18)H(36)N(8)O(4))]SO(4).4.5H(2)O, formed with the tetraamide cyclam derivative 2-(4,8,11-triscarbamoylmethyl-1,4,8,11-tetraazacyclotetradec-1-yl)acetamide (TETAM), is described. The macrocycle lies on an inversion centre occupied by the hexacoordinated Cu atom. The four macrocyclic tertiary amines form the equatorial plane of an axially Jahn-Teller elongated octahedron. Two O atoms belonging to two diagonally opposite amide groups occupy the apical positions, giving rise to a trans-III stereochemistry, while both the remaining pendant side arms extend outwards from the macrocyclic cavity and are engaged in hydrogen bonds with sulf…