Search results for "amer"

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…

Crítica musical y pensamiento estético en la España de la Restauración: José María Esperanza y Sola (1834-1905)

2015

One of the most outstanding figures of music criticism in the Spanish Restoration was José María Esperanza y Sola (1834-1905), active for thirty years, from the late 1860s until the end of the century. During this period, Esperanza collaborated in different periodical publications and, particularly, “La Ilustración Española y Americana”, from whose pages he informed about the most important musical events celebrated in Madrid, judged according to a conservative aesthetic criterion, opposed to any novelty that infringe the traditional music system. On the basis of Esperanza´s thought, our study analyzes the different subjects that constitute his journalistic production.La crítica musical en …

Fin del pensamiento unico

2001

Comparing Different Estimation Methodologies of Regional GDPs in Latin American Countries

2020

This chapter presents a survey of the different methods used to reconstitute long-run income estimations for the Latin American regions. The main purpose is to alert on potential biases derived from them. Although the bottom-up approaches based on the direct estimation of aggregate production, income or expenditure are the preferred option, they have barely been used. The main reason is that all of them are highly data-demanding. Instead, the indirect non-parametric approaches, combined sometimes with direct estimations for agriculture and extractive industries, have been the most recurrent way to estimate output. Out of the nine countries in the sample, seven have followed this “mixed appr…

“La feccia dell’Europa del Sud”. Razza e costruzione dell’identità etnica nella stampa italiana di New York (1890-1910)

2016

A partire dai primi anni di immigrazione di massa (1890), gli immigrati italiani furono sempre raffigurati nella stampa mainstream in associazione con la criminalità, in particolare la criminalità organizzata,. Le prime immagini dei nuovi arrivati visti come una minaccia per la sicurezza e la moralità americana, ​​col progredire del nuovo secolo, si diffusero sempre di più cristallizzandosi nella mente degli americani e finendo per diventare le rappresentazioni predominanti degli immigrati italiani. La risposta delle comunità italiane di nuova formazione si trova sulla stampa italo-americana, che fornì immagini alternative con cui la comunità italiana potesse identificarsi e prospettive alt…

“Insider Knowledge Versus Outsider Perspective in Early Italian American and African American Detective Stories”

2003

Relationship between the structure of amphiphilic copolymers and their ability to disturb lipid bilayers.

2005

Nonionic amphiphiles and particularly block copolymers of ethylene oxide and propylene oxide (Pluronics) cause pronounced chemosensitization of tumor cells that exhibit multiple resistance to antineoplastic drugs. This effect is due to inhibition of P-glycoprotein (P-gp) responsible for drug efflux. It was suggested that the inhibition of P-gp might be due to changes in its lipid surrounding. Indeed, high dependence of P-gp activity on the membrane microviscosity was demonstrated [Regev et al. (1999) Eur. J. Biochem. 259, 18-24], suggesting that the ability of Pluronics to affect the P-gp activity is mediated by their effect on the membrane structure. We have found recently that adsorption …

Long-Chain Alkyl Epoxides and Glycidyl Ethers: An Underrated Class of Monomers.

2020

Long-chain epoxides and specifically alkyl glycidyl ethers represent a class of highly hydrophobic monomers for anionic ring-opening polymerization (AROP), resulting in apolar aliphatic polyethers. In contrast, poly(ethylene glycol) is known for its high solubility in water. The combination of hydrophobic and hydrophilic monomers in block and statistical copolymerization reactions enables the synthesis of amphiphilic polyethers for a wide range of purposes, utilizing micellar interactions in aqueous solutions, e.g., viscosity enhancement of aqueous solutions, formation of supramolecular hydrogels, or for polymeric surfactants. Controlled polymerization of these highly hydrophobic long-chain…