Related Experiment Video
Updated: Jul 16, 2026
06:10
Assessment of Cellular Oxidation using a Subcellular Compartment-Specific Redox-Sensitive Green Fluorescent Protein
Published on: June 18, 2020
Recoverin as a redox-sensitive protein
Sergei E Permyakov1, Aliya A Nazipova, Alexander I Denesyuk
1Institute for Biological Instrumentation of the Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russia.
Journal of Proteome Research
|March 28, 2007
Summary
Recoverin, a neuronal calcium sensor protein, regulates vision by interacting with rhodopsin kinase. Its cysteine residue (Cys38) undergoes reversible oxidation, modulated by calcium, impacting its function in photoreceptor cells.
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Biology
Background:
- Recoverin is a neuronal calcium sensor (NCS) protein crucial for visual cycle regulation in photoreceptor cells.
- It modulates rhodopsin kinase activity in a calcium-dependent manner.
- Recoverin possesses a conserved cysteine residue (Cys38) in its EF-hand 1, whose role in protein interactions is investigated.
Purpose of the Study:
- To investigate the role of Cys38 in recoverin's function.
- To characterize the calcium-dependent reversible oxidation of recoverin's thiol group.
- To explore the implications of thiol oxidation for recoverin's activity in photoreceptor cells.
Main Methods:
- Spectrophotometric titration to determine the pKa of Cys38 thiol.
- SDS-PAGE under reducing and nonreducing conditions to analyze disulfide bond formation.
- Ellman's test to quantify thiol groups.
Main Results:
- The pKa of Cys38 thiol was determined to be 7.6, indicating partial deprotonation under physiological conditions.
- Recoverin can form a reversible disulfide dimer and a thiol-oxidized monomer under mild oxidizing conditions, modulated by calcium.
- Disulfide dimer formation is favored in Ca2+-bound recoverin, while oxidized monomer accumulation is more efficient in apo-recoverin.
Conclusions:
- Recoverin's thiol group undergoes calcium-modulated reversible oxidation.
- This reversible oxidation, forming dimers or monomers, may play a significant role in recoverin's function within photoreceptor cells.
- The differential formation of oxidation products based on calcium-binding status suggests a complex regulatory mechanism.
More Related Videos
10:24Defining Hsp33's Redox-regulated Chaperone Activity and Mapping Conformational Changes on Hsp33 Using Hydrogen-deuterium Exchange Mass Spectrometry
Published on: June 7, 2018
07:47Live Imaging of the Mitochondrial Glutathione Redox State in Primary Neurons using a Ratiometric Indicator
Published on: October 20, 2021
Related Concept Videos
01:27Redox Reactions
Redox reactions are vital biochemical processes that underpin energy metabolism in cells. These reactions involve the transfer of electrons between molecules, occurring in tandem as oxidation and reduction. Oxidation refers to the loss of electrons, while reduction denotes their gain. This coupling ensures the seamless flow of electrons through metabolic pathways. For example, in bacterial metabolism, glucose undergoes oxidation to carbon dioxide, while oxygen is simultaneously reduced to...
01:24Redox Reactions
Oxidation-reduction or redox reactions involve the transfer of electrons from one molecule or atom to another. When an atom gains an electron, another atom must lose an electron, meaning oxidation and reduction must occur together. Since the redox occurs in pairs, the atom that gets oxidized is also called the reducing agent or reductant, and the atom that is reduced is also called the oxidizing agent or oxidant. A straightforward way to remember the definitions of oxidation and reduction is...
01:23Redox Equilibria: Overview
A reduction-oxidation reaction is commonly called a redox reaction. In a redox reaction, electrons are transferred from one species to another rather than being shared between or among atoms. The reducing agent or reductant is the species that loses electrons and gets oxidized in the process. The species that gains electrons and gets reduced in the process is the oxidizing agent or oxidant. Redox reactions are represented as two separate equations called half-reactions, where one equation...
01:26Redox Titration: Other Oxidizing and Reducing Agents
Besides iodine, other oxidizing or reducing agents can serve as titrants in redox titrations. Common oxidizing titrants include KMnO4, cerium(IV), and K2Cr2O7. The choice of oxidizing titrants depends on factors like stability, cost, analyte strength, and reaction rate between the analyte and titrant. KMnO4 is a strong oxidizing titrant that reduces from Mn(VII) to Mn(II) in a highly acidic solution, simultaneously oxidizing the analyte to a higher oxidation state. In this case, KMnO4 acts as a...
01:21Redox Titration: Overview
Redox titration is a chemical analysis technique used to determine the concentration of an unknown substance by measuring the electron transfer in a redox (reduction-oxidation) reaction. The process involves gradually adding a titrant with a known concentration of an oxidizing or reducing agent, to the analyte, the solution with an unknown concentration, until reaching the endpoint, which indicates the completion of the reaction between the two substances. Ensuring the analyte is in a single...
02:58Balancing Redox Equations
Electrochemistry is the science involved in the interconversion of electrical and chemical reactions. Such reactions are called reduction-oxidation, or redox reactions. These important reactions are defined by changes in oxidation states for one or more reactant elements and include a subset of reactions involving the transfer of electrons between reactant species. Electrochemistry as a field has evolved to yield sufficient insights on the fundamental principles of redox chemistry and multiple...