Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Reactivity study on microperoxidase-8.

Corrado Dallacosta1, Enrico Monzani, Luigi Casella

  • 1Dipartimento di Chimica Generale, Università di Pavia, Via Taramelli 12, 27100, Pavia, Italy.

Journal of Biological Inorganic Chemistry : JBIC : a Publication of the Society of Biological Inorganic Chemistry
|September 25, 2003
PubMed
Summary

Microperoxidase-8 catalyzes tyramine and 3-(4-hydroxyphenyl)propionic acid oxidation. While turnover numbers were similar, substrate affinity varied due to electrostatic interactions, with faster reactions driven by minor active species.

Related Concept Videos

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

Area of Science:

  • Biocatalysis
  • Enzyme kinetics
  • Oxidation reactions

Background:

  • Microperoxidase-8 (MP8) is a heme-containing peptide with known catalytic activity.
  • Hydrogen peroxide (H2O2) is a common oxidant in biocatalytic systems.
  • Understanding MP8's reactivity with phenolic substrates is crucial for its application.

Purpose of the Study:

  • To determine the catalytic activity of the microperoxidase-8/H2O2 system towards tyramine and 3-(4-hydroxyphenyl)propionic acid.
  • To investigate the kinetic parameters (kcat, KM) and substrate affinity.
  • To identify and characterize the active species involved in the catalytic cycle.

Main Methods:

  • Enzyme kinetics assays were performed in acetate buffer at pH 5.0.
  • Substrate oxidation rates were measured under conditions of excess hydrogen peroxide.

Related Experiment Videos

  • Kinetic analysis involved determining turnover numbers and Michaelis constants (KM).

    • Main Results:

    • The MP8/H2O2 system exhibited substrate saturation kinetics for both tyramine and 3-(4-hydroxyphenyl)propionic acid.
    • Similar turnover numbers (kcat ≈ 22-26 s−1) were observed for both substrates.
    • Lower affinity (higher KM) for tyramine was attributed to repulsive interactions with the protonated MP8 amino group.

    Conclusions:

    • The catalytic cycle involves multiple active species, with minor species (I and II) being more active than the predominant intermediate III.
    • Intermediate III, accumulating in larger amounts, has reduced activity and is not part of the main catalytic cycle.
    • MP8 degradation necessitates analysis of initial reaction phases, highlighting the complexity of its catalytic mechanism.