Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Protein Denaturation

Protein Denaturation

The function of proteins depends on their native three-dimensional structure, which is dictated by the amino acid sequence of the specific protein. Folding of the polypeptide chain takes place under specific conditions that energetically favor the folded conformation. In contrast, protein denaturation occurs spontaneously under unfavorable conditions that disrupt the integrity of the folded conformation. Thus, the chemical and physical environment of a protein, such as significant changes in pH...

Gene Families

Gene Families

Gene families consist of groups of genes proposed to have originated from a common ancestor. Typically these arise through events in which a gene or genes are mistakenly duplicated during cell division. Unlike their parent genes (which are subject to selection pressure to maintain function), these gene copies do not need to preserve their sequences and may evolve at a relatively faster rate.
Occasionally these regions can be adapted to take on new roles within the organism, becoming novel genes...

Drugs Affecting Neurotransmitter Synthesis

Drugs Affecting Neurotransmitter Synthesis

Drugs affecting neurotransmitter synthesis can impact the adrenergic neuron and the synthesis of neurotransmitters. For example, α-methyltyrosine and carbidopa target specific enzymes involved in catecholamine synthesis. α-methyltyrosine inhibits the enzyme tyrosine hydroxylase, which converts tyrosine into dopamine. By blocking this enzyme, α-methyltyrosine reduces dopamine production and other catecholamines. Carbidopa, on the other hand, inhibits the enzyme dopa decarboxylase, which converts...

Hemoglobin

Hemoglobin

Hemoglobin is a globular protein made up of four subunits. Two of these subunits are alpha chains, and the other two are beta chains. Each subunit contains a molecule of heme, which has an iron atom and can bind to oxygen. When an oxygen molecule binds to one heme group, it changes the shape of hemoglobin, making it easier for the other heme groups to bind oxygen as well.
When all four heme groups are bound to oxygen, the resulting molecule is called oxyhemoglobin. As a result, arterial blood...

Protein Modifications in the RER

Protein Modifications in the RER

Modification of secretory and transmembrane proteins entering the rough ER begins in the ER lumen. These modifications aid in protein folding and stabilize the acquired tertiary structure. Protein modifications in the rough ER co-occur at different stages of protein folding.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal sequences.

Covalently Linked Protein Regulators

Covalently Linked Protein Regulators

Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Copper Coordination to the Prion Fragment (95-126): Implications for Neurodegenerative Diseases.

International journal of molecular sciences·2026

Same author

Neuromelanin, iron and MRI measurements in midbrain tissues of Parkinson's and Alzheimer's subjects.

Frontiers in aging neuroscience·2026

Same author

Influence of Nitrative Stress on the Synthesis of Neuromelanin Model Systems.

ACS chemical neuroscience·2025

Same author

Modeling Midbrain and Brainstem Neuromelanins to Characterize Metal Binding and Associated MRI Contrast in Parkinson's and Alzheimer's Diseases.

Angewandte Chemie (International ed. in English)·2025

Same author

How Sodium Dodecyl Sulfate Micelles Affect the Coordination and Peroxidase-Like Activity of the Hemin-Aβ16 Complex.

ChemPlusChem·2025

Same author

A Focus on the Link Between Metal Dyshomeostasis, Norepinephrine, and Protein Aggregation.

Antioxidants (Basel, Switzerland)·2025

Search research articles

Related Experiment Video

Updated: Jul 3, 2026

Genetic Incorporation of Biosynthesized L-dihydroxyphenylalanine (DOPA) and Its Application to Protein Conjugation

Genetic Incorporation of Biosynthesized L-dihydroxyphenylalanine (DOPA) and Its Application to Protein Conjugation

Published on: August 24, 2018

Myoglobin modification by enzyme-generated dopamine reactive species.

Stefania Nicolis¹, Matteo Zucchelli, Enrico Monzani

¹Dipartimento di Chimica Generale, Università di Pavia, Via Taramelli 12, Pavia, Italy.

Chemistry (Weinheim an Der Bergstrasse, Germany)

|August 9, 2008

Summary

Reactive dopamine quinones (DAQ), implicated in Parkinson's disease, form adducts with thiols and proteins. The oxidation pathway influences reaction products, with radical mechanisms yielding cystine dimers and protein modifications leading to instability and aggregation.

More Related Videos

Synthesizing Amino Acids Modified with Reactive Carbonyls in Silico to Assess Structural Effects Using Molecular Dynamics Simulations

Synthesizing Amino Acids Modified with Reactive Carbonyls in Silico to Assess Structural Effects Using Molecular Dynamics Simulations

Published on: April 26, 2024

Visualization of Mitochondrial Respiratory Function using Cytochrome C Oxidase / Succinate Dehydrogenase (COX/SDH) Double-labeling Histochemistry

Visualization of Mitochondrial Respiratory Function using Cytochrome C Oxidase / Succinate Dehydrogenase (COX/SDH) Double-labeling Histochemistry

Published on: November 23, 2011

Related Experiment Videos

Last Updated: Jul 3, 2026

Genetic Incorporation of Biosynthesized L-dihydroxyphenylalanine (DOPA) and Its Application to Protein Conjugation

Genetic Incorporation of Biosynthesized L-dihydroxyphenylalanine (DOPA) and Its Application to Protein Conjugation

Published on: August 24, 2018

Synthesizing Amino Acids Modified with Reactive Carbonyls in Silico to Assess Structural Effects Using Molecular Dynamics Simulations

Synthesizing Amino Acids Modified with Reactive Carbonyls in Silico to Assess Structural Effects Using Molecular Dynamics Simulations

Published on: April 26, 2024

Visualization of Mitochondrial Respiratory Function using Cytochrome C Oxidase / Succinate Dehydrogenase (COX/SDH) Double-labeling Histochemistry

Visualization of Mitochondrial Respiratory Function using Cytochrome C Oxidase / Succinate Dehydrogenase (COX/SDH) Double-labeling Histochemistry

Published on: November 23, 2011

Area of Science:

Biochemistry
Neuroscience
Protein Chemistry

Background:

Dopamine (DA) oxidation generates reactive quinone species (DAQ) implicated in neurodegenerative diseases like Parkinson's.
DAQ formation can proceed via a two-electron or two one-electron steps, influencing reaction pathways.

Purpose of the Study:

To characterize thiol-catechol adducts formed by DA and cysteine/glutathione.
To identify amino acid residues modified by DAQs in myoglobin.
To investigate the impact of DAQ modification on protein stability.

Main Methods:

Enzymatic oxidation of dopamine using tyrosinase and peroxidases.
Characterization of adducts using techniques like mass spectrometry (implied).
Analysis of protein modifications in human and horse heart myoglobin.

Main Results:

Cysteinyl-DA adducts form from a common quinone intermediate regardless of the DA oxidation mechanism.
Radical oxidation mechanisms are distinguished by cystine dimer formation.
Histidine residues are susceptible to DAQ derivatization; a radical intramolecular mechanism modifies cysteine in human myoglobin.
Myoglobin modification by DAQ linkages and oligomers induces unfolding and aggregation into insoluble precipitates.

Conclusions:

The mechanism of dopamine oxidation dictates the products and protein modification patterns.
Dopamine quinone modification significantly destabilizes myoglobin structure, leading to aggregation.
Understanding these reactions is crucial for neurodegenerative disease research.