Reactive oxygen, nitrogen, and sulfur species, referred to as ROS, RNS, and RSS, respectively, are produced during normal cell function and in response to various stimuli. An imbalance in the metabolism of these reactive intermediates results in the phenomenon known as oxidative stress. If left unchecked, oxidative molecules can inflict damage on all classes of biological macromolecules and eventually lead to cell death. Indeed, sustained elevated levels of reactive species have been implicated in the etiology (e.g., atherosclerosis, hypertension, diabetes) or the progression (e.g., stroke, cancer, and neurodegenerative disorders) of a number of human diseases.1 Over the past several decades, however, a new paradigm has emerged in which the aforementioned species have also been shown to function as targeted, intracellular second messengers with regulatory roles in an array of physiological processes.2 Against this backdrop, it is not surprising that considerable ongoing efforts are aimed at elucidating the role that these reactive intermediates play in health and disease.

Site-specific, covalent modification of proteins represents a prominent molecular mechanism for transforming an oxidant signal into a biological response. Amino acids that are candidates for reversible modification include cysteines whose thiol (i.e., sulfhydryl) side chain is deprotonated at physiological pH, which is an important attribute for enhancing reactivity. While reactive species can modify other amino acids (e.g., histidine, methionine, tryptophan, and tyrosine), this Review will focus exclusively on cysteine, whose identity as cellular target or “sensor” of reactive intermediates is most prevalent and established.3 Oxidation of thiols results in a range of sulfur-containing products, not just disulfide bridges, as typically presented in biochemistry textbooks. An overview of the most relevant forms of oxidized sulfur species found in vivo is presented in Chart 1.






Open in a separate window


Chart 1

Biologically Relevant Cysteine Chemotypesa

aRed, irreversible modifications. Green, unique enzyme intermediates. Note: Additional modifications can form as enzyme intermediates including thiyl radicals, disulfides, and persulfides.

Cysteine-Mediated Redox Signaling: Chemistry, Biology, and Tools for Discovery

Oxidative and nitrosative stress induced by ROS/RNS play crucial roles in a wide range of physiological processes and are also implicated in various diseases, including cancer and neurodegenerative disorders. Sensitive and selective methods for the detection of ROS/RNS based on fluorescent and luminescent probes are of great use in monitoring the in vivo production of these species and elucidating their biological functions. This critical review highlights recent advances that have been made in the development of fluorescent and luminescent probes employed to monitor various ROS/RNS (132 references).

Fluorescent and luminescent probes for detection of reactive oxygen and nitrogen species

Antioxidant capacity is related with compounds capable of protecting a biological system against the potentially harmful effect of processes or reactions involving reactive oxygen and nitrogen species (ROS and RNS). These protective effects of antioxidants have received increasing attention within biological, medical, nutritional, and agrochemical fields and resulted in the requirement of simple, convenient, and reliable antioxidant capacity determination methods. Many methods which differ from each other in terms of reaction mechanisms, oxidant and target/probe species, reaction conditions, and expression of results have been developed and tested in the literature. In this review, the methods most widely used for the determination of antioxidant capacity are evaluated, presenting the general principals, recent applications, and their strengths and limitations. Analysis conditions, substrate, and antioxidant concentration should simulate real food or biological systems as much as possible when selecting the antioxidant capacity method. The total antioxidant capacity value should include methods applicable to both lipophilic and hydrophilic antioxidants, with regards the similarity and differences of both hydrogen atom transfer and electron transfer mechanism. The methods including various ROS/RNS also have to be designed to comprehensively evaluate the antioxidant capacity of a sample.

Review of methods to determine antioxidant capacities.

Cold atmospheric plasma activated water as a prospective disinfectant: the crucial role of peroxynitrite

Reactive nitrogen species in plasma-activated water: generation, chemistry and application in agriculture

A novel fluorescent method for determination of peroxynitrite using folic acid as a probe

V3 CTL epitope density in a single recombinant molecule antigen differentially affects the number and activity of primary and memory CD8+ T cells.

Synthetic biologists aim to design biological systems for a variety of industrial and medical applications, ranging from biofuel to drug production. Synthetic gene circuits regulating efflux pump protein expression can achieve this by driving desired substrates such as biofuels, pharmaceuticals, or other chemicals out of the cell in a precisely controlled manner. However, efflux pumps may introduce implicit negative feedback by pumping out intracellular inducer molecules that control gene circuits, which then can alter gene circuit function. Therefore, synthetic gene circuits must be carefully designed and constructed for precise efflux control. Here, we provide protocols for quantitatively modeling and building synthetic gene constructs for efflux pump regulation.

/pdf/negative-regulation-gene-circuits-for-efflux-pump-control-5fecbrh5jn.pdf

Negative Regulation Gene Circuits for Efflux Pump Control

Synthetic biology aims to design new biological systems for predefined purposes, such as the controlled secretion of biofuels, pharmaceuticals, or other chemicals. Synthetic gene circuits regulating an efflux pump from the ATP-binding cassette (ABC) protein family could achieve this. However, ABC efflux pumps can also drive out intracellular inducer molecules that control the gene circuits. This will introduce an implicit feedback that could alter gene circuit function in ways that are poorly understood. Here, we used two synthetic gene circuits inducible by tetracycline family molecules to regulate the expression of a yeast ABC pump (Pdr5p) that pumps out the inducer. Pdr5p altered the dose–responses of the original gene circuits substantially in Saccharomyces cerevisiae. While one aspect of the change could be attributed to the efflux pumping function of Pdr5p, another aspect remained unexplained. Quantitative modeling indicated that reduced regulator gene expression in addition to efflux pump function ...

/pdf/efflux-pump-control-alters-synthetic-gene-circuit-function-rxef3uide5.pdf

Efflux Pump Control Alters Synthetic Gene Circuit Function

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Junchen Diao

Author Tools

Chat about Author

Papers

A novel fluorescent method for determination of peroxynitrite using folic acid as a probe

V3 CTL epitope density in a single recombinant molecule antigen differentially affects the number and activity of primary and memory CD8+ T cells.

Negative Regulation Gene Circuits for Efflux Pump Control

Efflux Pump Control Alters Synthetic Gene Circuit Function