Evaluating antioxidative activities of amino acid substitutions on mastoparan-B
Mars J Yang1, Wen-Yuh Lin, Kuang-Hui Lu
1Department of Entomology, National Chung Hsing University, Taichung, Taiwan, ROC.
Abstract:
Mastoparan-B is a peptide toxin isolated from the venom of Vespa basalis, the most dangerous hornet found in Taiwan. This study is aimed to evaluate the antioxidative activities of several amino acid substitutions on MP-B, and examined the influences of mast cell degranulation and hemolytic activities in parallel with antioxidative activities. The correlations between the biological function and amino acid sequence were assessed. Our study shows original MP-B is a valuable antioxidant at low concentration in competing with nitric-oxide for oxygen molecules and possesses good antioxidative enzyme activities resembled to superoxidase dismutase and glutathione peroxidase. And there are no predominant rates of mast cell degranulation and hemolytic effects in such condition. With proper substitutions, the reducing power, DPPH scavenging activity and glutathione reductase-like enzyme activity of MP-B can increase clearly. The results demonstrate that MP-B analogs are very potential to be applicable antioxidants for other antioxidative usages.
Insights
Mastoparan-B, a hornet venom peptide, shows antioxidant properties by scavenging nitric oxide and mimicking antioxidant enzymes. Amino acid substitutions enhance its antioxidant capacity, indicating potential for new antioxidant applications.
Area of Science:
- Biochemistry
- Toxicology
- Pharmacology
Background:
- Mastoparan-B (MP-B) is a peptide toxin from Vespa basalis venom.
- Its potential as an antioxidant and its biological activities require further investigation.
Purpose of the Study:
- To evaluate the antioxidant activities of MP-B with amino acid substitutions.
- To assess mast cell degranulation and hemolytic activities in parallel.
- To correlate biological function with amino acid sequence.
Main Methods:
- Amino acid substitutions were introduced into MP-B.
- Antioxidative activities (reducing power, DPPH scavenging, enzyme mimicry) were measured.
- Mast cell degranulation and hemolytic assays were performed.
Main Results:
- Native MP-B acts as an antioxidant, competing with nitric oxide and exhibiting superoxide dismutase and glutathione peroxidase-like activities.
- MP-B showed minimal mast cell degranulation and hemolytic effects at low concentrations.
- Specific substitutions significantly enhanced reducing power, DPPH scavenging, and glutathione reductase-like activity.
Conclusions:
- MP-B possesses inherent antioxidant properties and low toxicity.
- MP-B analogs demonstrate significantly improved antioxidant potential.
- These modified peptides are promising candidates for antioxidant applications.
