Search results for "Acetylation"

Influence of enol acetylation on the photo-fries rearrangement of anortho-acylaryl benzoate

1982

The enol acetate 1b undergoes benzoyl-oxygen bond rupture upon irradiation, giving a mixture of benzophenones 4 and 5. The primary photo-Fries products 2 and 3 could not be isolated, due to a rapid intramolecular transacetylation. The acetophenone 6 rearranges to give the benzophenones 7 and 8 under the same conditions, but the yields are significantly lower than in the former case. Compounds 7 and 8 are separately correlated with 4 and 5 by treatment with acetic anhydride in the presence of pyridine. Einflus der Enol-Acetylierung auf die Photo-Fries-Umlagerung eines Benzoesaure-ortho-acylarylesters Das Enolacetat 1b erleidet bei Bestrahlung Spaltung der Benzoyl-Sauerstoff-Bindung, wobei ei…

A p300 and SIRT1 Regulated Acetylation Switch of C/EBPP Controls Mitochondrial Function

2018

Cellular metabolism is a tightly controlled process in which the cell adapts fluxes through metabolic pathways in response to changes in nutrient supply. Among the transcription factors that regulate gene expression and thereby cause changes in cellular metabolism is the basic leucine-zipper (bZIP) transcription factor CCAAT/enhancer-binding protein alpha (C/EBPα). Protein lysine acetylation is a key post-translational modification (PTM) that integrates cellular metabolic cues with other physiological processes. Here we show that C/EBPα is acetylated by the lysine acetyl transferase (KAT) p300 and deacetylated by the lysine deacetylase (KDAC) Sirtuin1 (SIRT1). SIRT1 is activated in times of…

ChemInform Abstract: Photochemistry of 7-Acetoxybenzopyran Derivatives. Synthesis of Eupatoriochromene and Encecalin.

1990

Abstract The photolysis of the 7-acetoxybenzopyran derivatives 1a-5a has been carried out. Chromene 1a was found to undergo extensive photopolymerization. Chromanone 2a underwent a rather inefficient photo-Fries rearrangement to the 6 - and 8 - acetyl derivatives 2b and 2c . Diacetoxychromene 3a gave the unsaturated ketone 8 as the main product, besides its deacetylation analogue 9 and chromanone 11 . Diacetoxychroman 4a afforded a mixture of four C-acetyl products: 1b, 1c, 2b and 2c , together with Chromene 1a and chromanone 2a. Finally, irradiation of chroman 5a gave rise to a mixture of the two possible photo-Fries products 5b (43%) and 5c (52%). The mechanistic implications of the above…

On the ubiquitous presence of histone acetyltransferase B in eukaryotes

1985

AbstractHistone acetyltransferase B activity has been found in pea (Pisun sativum) seedlings. The enzyme has been partially purified and it has been found that it is highly specific for H4. The results confirm that histone acetyltransferase B occurs in 3 eukaryotic kingdoms.

SAP30L interacts with members of the Sin3A corepressor complex and targets Sin3A to the nucleolus.

2006

Histone acetylation plays a key role in the regulation of gene expression. The chromatin structure and accessibility of genes to transcription factors is regulated by enzymes that acetylate and deacetylate histones. The Sin3A corepressor complex recruits histone deacetylases and in many cases represses transcription. Here, we report that SAP30L, a close homolog of Sin3-associated protein 30 (SAP30), interacts with several components of the Sin3A corepressor complex. We show that it binds to the PAH3/HID (Paired Amphipathic Helix 3/Histone deacetylase Interacting Domain) region of mouse Sin3A with residues 120–140 in the C-terminal part of the protein. We provide evidence that SAP30L induces…

Citrus peels as biocatalyst for deacetylation reactions

2014

Uncapping the N-terminus of a ubiquitous His-tag peptide enhances its Cu2+ binding affinity

2019

Metal complexes with an N-terminally free and N-terminally acetylated polyhistidine region of Echis ocellatus venom, with an interesting His-rich motif present in numerous metal binding proteins from all kingdoms of life (DHDHDHHHHHHPGSSV-NH2 and Ac-DHDHDHHHHHHPGSSV-NH2) show the role of the free amino group in the thermodynamic enhancement of Cu2+, Ni2+ and Zn2+ binding. In the studied sequences, Cu2+ can be coordinated by different sets of imidazole rings, and a 3–10 helix is detected in close proximity of Cu2+ binding sites. The complexes are more stable than those with a typical His6-tag, despite a similar copper(II) coordination mode in both cases.

EGF-Induced Acetylation of Heterogeneous Nuclear Ribonucleoproteins Is Dependent on KRAS Mutational Status in Colorectal Cancer Cells.

2015

KRAS mutational status is considered a negative predictive marker of the response to anti-EGFR therapies in colorectal cancer (CRC) patients. However, conflicting data exist regarding the variable response to EGFR-targeted therapy. The effects of oncogenic KRAS on downstream targets were studied in cell lines with different KRAS mutations. Cells harboring a single KRASG13D allele showed the most tumorigenic profile, with constitutive activation of the downstream pathway, rendering them EGF-unresponsive. Conversely, KRASA146T cells showed a full EGF-response in terms of signal transduction pathways, cell proliferation, migration or adhesion. Moreover, the global acetylome of CRC cells was al…

Synthesis, computational evaluation and pharmacological assessment of acetylsalicylic esters as anti-inflammatory agents

2019

A convenient approach to the synthesis of alkyl esters of aspirin (ASA-OR) has been developed. The synthesis of ASA-OR has been realized in two steps: (1) direct esterification of salicylic acid with alcohols in the presence of dicyclohexylcarbodiimide to give alkyl salicylates (SAL-OR); (2) acetylation of SAL-OR with acetyl chloride to yield ASA-OR. Molecular mechanics simulations, performed to calculate the kinetic radii of several ASA-OR, indicated that the pentyl and hexyl acetylsalicylates possess the best properties to cross cell membranes. The in vitro biological tests demonstrate their anti-inflammatory activity, superimposable to that of aspirin. The results of our study suggest th…

Hepatocyte growth factor induces MAT2A expression and histone acetylation in rat hepatocytes: role in liver regeneration 1

2001

SPECIFIC AIMSWe have studied the molecular mechanisms and mediators behind the induction of methionine adenosyltransferase 2 A (MAT2A) gene expression in the regenerating rat liver after partial he...