Site-specific hydrogen-atom elimination in photoexcited alkyl radicals

2021 ◽  
Vol 23 (3) ◽  
pp. 2458-2468
Author(s):  
David V. Chicharro ◽  
Alexandre Zanchet ◽  
Aymen Bouallagui ◽  
Luis Rubio-Lago ◽  
Alberto García-Vela ◽  
...  

A prompt site-specific hydrogen-atom elimination from the α-carbon atom is reported in the photodissociation of several alkyl radicals at 201 nm and discussed in terms of their chemical structure and the role of vibrational promoting modes.

2016 ◽  
Vol 86 (3-4) ◽  
pp. 127-151 ◽  
Author(s):  
Zeshan Ali ◽  
Zhenbin Wang ◽  
Rai Muhammad Amir ◽  
Shoaib Younas ◽  
Asif Wali ◽  
...  

While the use of vinegar to fi ght against infections and other crucial conditions dates back to Hippocrates, recent research has found that vinegar consumption has a positive effect on biomarkers for diabetes, cancer, and heart diseases. Different types of vinegar have been used in the world during different time periods. Vinegar is produced by a fermentation process. Foods with a high content of carbohydrates are a good source of vinegar. Review of the results of different studies performed on vinegar components reveals that the daily use of these components has a healthy impact on the physiological and chemical structure of the human body. During the era of Hippocrates, people used vinegar as a medicine to treat wounds, which means that vinegar is one of the ancient foods used as folk medicine. The purpose of the current review paper is to provide a detailed summary of the outcome of previous studies emphasizing the role of vinegar in treatment of different diseases both in acute and chronic conditions, its in vivo mechanism and the active role of different bacteria.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Eva Höllmüller ◽  
Simon Geigges ◽  
Marie L. Niedermeier ◽  
Kai-Michael Kammer ◽  
Simon M. Kienle ◽  
...  

AbstractDecoding the role of histone posttranslational modifications (PTMs) is key to understand the fundamental process of epigenetic regulation. This is well studied for PTMs of core histones but not for linker histone H1 in general and its ubiquitylation in particular due to a lack of proper tools. Here, we report on the chemical synthesis of site-specifically mono-ubiquitylated H1.2 and identify its ubiquitin-dependent interactome on a proteome-wide scale. We show that site-specific ubiquitylation of H1 at position K64 modulates interactions with deubiquitylating enzymes and the deacetylase SIRT1. Moreover, it affects H1-dependent chromatosome assembly and phase separation resulting in a more open chromatosome conformation generally associated with a transcriptionally active chromatin state. In summary, we propose that site-specific ubiquitylation plays a general regulatory role for linker histone H1.


Author(s):  
Giulia Maria Pires dos Santos ◽  
Gustavo Ramalho Cardoso dos Santos ◽  
Mariana Ingrid Dutra da Silva Xisto ◽  
Rodrigo Rollin-Pinheiro ◽  
Andréa Regina de Souza Baptista ◽  
...  

1988 ◽  
Vol 263 (36) ◽  
pp. 19662-19669
Author(s):  
T L Solomon ◽  
L R Solomon ◽  
L S Gay ◽  
P A Rubenstein
Keyword(s):  

Biomolecules ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 15
Author(s):  
Aishat Motolani ◽  
Matthew Martin ◽  
Mengyao Sun ◽  
Tao Lu

The nuclear factor kappa B (NF-κB) is a ubiquitous transcription factor central to inflammation and various malignant diseases in humans. The regulation of NF-κB can be influenced by a myriad of post-translational modifications (PTMs), including phosphorylation, one of the most popular PTM formats in NF-κB signaling. The regulation by phosphorylation modification is not limited to NF-κB subunits, but it also encompasses the diverse regulators of NF-κB signaling. The differential site-specific phosphorylation of NF-κB itself or some NF-κB regulators can result in dysregulated NF-κB signaling, often culminating in events that induce cancer progression and other hyper NF-κB related diseases, such as inflammation, cardiovascular diseases, diabetes, as well as neurodegenerative diseases, etc. In this review, we discuss the regulatory role of phosphorylation in NF-κB signaling and the mechanisms through which they aid cancer progression. Additionally, we highlight some of the known and novel NF-κB regulators that are frequently subjected to phosphorylation. Finally, we provide some future perspectives in terms of drug development to target kinases that regulate NF-κB signaling for cancer therapeutic purposes.


2006 ◽  
Vol 291 (6) ◽  
pp. F1123-F1132 ◽  
Author(s):  
James J. De Yoreo ◽  
S. Roger Qiu ◽  
John R. Hoyer

Calcium oxalate monohydrate (COM) is the primary constituent of the majority of renal stones. Osteopontin (OPN), an aspartic acid-rich urinary protein, and citrate, a much smaller molecule, are potent inhibitors of COM crystallization at levels present in normal urine. Current concepts of the role of site-specific interactions in crystallization derived from studies of biomineralization are reviewed to provide a context for understanding modulation of COM growth at a molecular level. Results from in situ atomic force microscopy (AFM) analyses of the effects of citrate and OPN on growth verified the critical role of site-specific interactions between these growth modulators and individual steps on COM crystal surfaces. Molecular modeling investigations of interactions of citrate with steps and faces on COM crystal surfaces provided links between the stereochemistry of interaction and the binding energy levels that underlie mechanisms of growth modification and changes in overall crystal morphology. The combination of in situ AFM and molecular modeling provides new knowledge that will aid rationale design of therapeutic agents for inhibition of stone formation.


2017 ◽  
Vol 139 ◽  
pp. 84-88 ◽  
Author(s):  
S. Samaneh Ataei ◽  
S. Javad Hashemifar ◽  
Mohammad Reza Mohammadizadeh

1993 ◽  
Vol 13 (3) ◽  
pp. 1363-1370 ◽  
Author(s):  
K M Sheehan ◽  
M R Lieber

V(D)J recombination in lymphoid cells is a site-specific process in which the activity of the recombinase enzyme is targeted to signal sequences flanking the coding elements of antigen receptor genes. The order of the steps in this reaction and their mechanistic interdependence are important to the understanding of how the reaction fails and thereby contributes to genomic instability in lymphoid cells. The products of the normal reaction are recombinant joints linking the coding sequences of the receptor genes and, reciprocally, the signal ends. Extrachromosomal substrate molecules were modified to inhibit the physical synapsis of the recombination signals. In this way, it has been possible to assess how inhibiting the formation of one joint affects the resolution efficiency of the other. Our results indicate that signal joint and coding joint formation are resolved independently in that they can be uncoupled from each other. We also find that signal synapsis is critical for the generation of recombinant products, which greatly restricts the degree of potential single-site cutting that might otherwise occur in the genome. Finally, inversion substrates manifest synaptic inhibition at much longer distances than do deletion substrates, suggesting that a parallel rather than an antiparallel alignment of the signals is required during synapsis. These observations are important for understanding the interaction of V(D)J signals with the recombinase. Moreover, the role of signal synapsis in regulating recombinase activity has significant implications for genome stability regarding the frequency of recombinase-mediated chromosomal translocations.


Sign in / Sign up

Export Citation Format

Share Document