Related Experiment Video

Updated: Jun 23, 2026

Determining the Serum Stability of Human Adenosine Deaminase 1 Enzyme
04:17

Determining the Serum Stability of Human Adenosine Deaminase 1 Enzyme

Published on: September 27, 2024

Paraoxonase-1 activity determination via paraoxon substrate yields no significant difference in mild

Hatice Türkeli, Tuncer Caycı, Emin Özgür Akgül

    International Journal of Cardiology
    |May 8, 2009
    PubMed

    Insights

    Mild hyperhomocysteinemia, a risk factor for cardiovascular disease, did not significantly alter serum paraoxonase (PON) enzyme activity in a human population study. This suggests PON

    Area of Science:

    • Biochemistry
    • Cardiovascular Research
    • Nutritional Science

    Background:

    • Elevated plasma homocysteine (Hcy) is a risk factor for cardiovascular diseases.
    • Homocysteine thiolactone (HcyT) is formed from Hcy and hydrolyzed back by paraoxonase (PON) enzyme.
    • PON acts as a protective enzyme against hyperhomocysteinemia.

    Purpose of the Study:

    • To investigate the effect of a mild hyperhomocysteinemic diet on serum PON activity.
    • To assess the enzyme's performance in a population-based study.
    • To understand the body's protective mechanisms against elevated Hcy levels.

    Main Methods:

    • A population-based study involving a mild hyperhomocysteinemic nutritional habit.
    • Determination of serum PON activity using the paraoxon substrate.
    • Statistical analysis of enzymatic activity differences.

    Main Results:

    • Enzymatic activity measured via paraoxon substrate showed no statistically significant difference (p=0.19).
    • The study found no significant change in serum PON activity in response to the mild hyperhomocysteinemic diet.
    • Results suggest a potentially defective performance in reflecting expected significance.

    Conclusions:

    • Serum PON activity did not significantly change in an acute mild hyperhomocysteinemic diet model in humans.
    • The findings indicate that PON enzyme activity may not be a sensitive marker for mild, acute hyperhomocysteinemia.
    • Further research is needed to fully elucidate the role of PON in hyperhomocysteinemia and cardiovascular health.

    More Related Videos

    The Nijmegen Hemostasis Assay: Simultaneous Fluorogenic Measurement of Thrombin and Plasmin Generation in a Single Well08:01

    The Nijmegen Hemostasis Assay: Simultaneous Fluorogenic Measurement of Thrombin and Plasmin Generation in a Single Well

    Published on: February 27, 2026

    A Semi-High-Throughput Adaptation of the NADH-Coupled ATPase Assay for Screening Small Molecule Inhibitors10:28

    A Semi-High-Throughput Adaptation of the NADH-Coupled ATPase Assay for Screening Small Molecule Inhibitors

    Published on: August 17, 2019

    Related Concept Videos

    Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes01:28

    Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes

    Cytochrome P450 (CYP450) enzymes are a superfamily of heme-containing monooxygenases that play a pivotal role in Phase I drug metabolism by catalyzing oxidation and reduction reactions.These enzymes transform lipophilic xenobiotics into more hydrophilic metabolites, facilitating subsequent Phase II conjugation and eventual excretion. The CYP450 family is classified into families (e.g., CYP1–CYP3) and subfamilies (e.g., CYP2A, CYP2C), based on amino acid sequence homology.CYP450 isoenzymes,...
    Enzyme Inhibition01:30

    Enzyme Inhibition

    Inhibitors are molecules that reduce enzyme activity by binding to the enzyme. In a normally functioning cell, enzymes are regulated by a variety of inhibitors. Drugs and other toxins can also inhibit enzymes. Some inhibitors bind to the enzyme’s active site, while others inhibit enzymatic activity by binding to other sites on the protein structure.
    Nonlinear Pharmacokinetics: Dependence of Elimination Half-Life and Dose Clearance01:23

    Nonlinear Pharmacokinetics: Dependence of Elimination Half-Life and Dose Clearance

    The elimination half-life and drug clearance of drugs following nonlinear kinetics can vary with dosage. The Michaelis-Menten parameters and drug concentration influence these factors. As the dose increases, the elimination half-life tends to lengthen, resulting in a reduction in clearance and a disproportionately larger area under the curve. The total clearance can be derived from the Michaelis-Menten equation for drugs following a one-compartment model.
    A study on guinea pigs examined the...