A lectin from Spatholobus parviflorus inhibits Aspergillus flavus α-amylase: enzyme kinetics and thermodynamic studies
Ignatius Tintu1, Joseph Abhilash, Kalarickal V Dileep
1Department of Biotechnology & Microbiology, Inter-University Centre for Bioscience, Kannur University, Thalassery Campus, Palayad, 670661, India.
Abstract:
Aspergillus flavus is a commonly found fungal pathogen which produces structurally related and highly toxic secondary metabolites, aflatoxins. It has been proposed that α-amylase inhibitors may limit the ability of the fungus to produce aflatoxins. Hence, this enzyme is a potent target for the development of antifungal agents. In this study, it was found that Spatholobus parviflorus seed lectin (SPL) can inhibit the growth of A. flavus with a MIC value of 1.5 mg/mL. The enzyme kinetics, molecular modeling and isothermal titration calorimetric studies suggest that SPL can inhibit α-amylase with Ki value of 0.0042 mm. Hence, it is suggested that the antifungal activity of SPL might be partly due to its ability to inhibit the enzyme α-amylase.
Insights
Spatholobus parviflorus seed lectin (SPL) inhibits Aspergillus flavus growth and its toxic aflatoxin production by targeting the fungal alpha-amylase enzyme. This lectin shows potential as a novel antifungal agent.
Area of Science:
- Mycology
- Biochemistry
- Pharmacology
Background:
- Aspergillus flavus produces toxic aflatoxins, posing a significant threat to agriculture and human health.
- Alpha-amylase inhibitors are hypothesized to reduce aflatoxin production by A. flavus.
- Developing novel antifungal agents targeting key fungal enzymes is crucial.
Discussion:
- Spatholobus parviflorus seed lectin (SPL) demonstrated significant antifungal activity against A. flavus, with a Minimum Inhibitory Concentration (MIC) of 1.5 mg/mL.
- Enzyme kinetics, molecular modeling, and isothermal titration calorimetry revealed that SPL inhibits alpha-amylase with a low inhibition constant (Ki) of 0.0042 mM.
- The study suggests that SPL's antifungal properties are, at least in part, mediated by its inhibition of fungal alpha-amylase.
Key Insights:
- SPL effectively inhibits the growth of Aspergillus flavus.
- SPL acts as a potent inhibitor of the alpha-amylase enzyme.
- Alpha-amylase inhibition is a potential mechanism for SPL's antifungal activity.
Outlook:
- SPL represents a promising candidate for developing new antifungal strategies against A. flavus.
- Further research into SPL's mechanism of action and in vivo efficacy is warranted.
- Targeting fungal alpha-amylase could be a viable approach for controlling aflatoxin contamination.
