Exploration of antioxidant peptides from crocodile (Crocodylus siamensis) meat using modern information technology: Virtual-screening and antioxidant mechanisms

• Published in: Food research international 2025-02, Vol.202, p.115789, Article 115789
• Main Authors: Mengli, Zhang, Ji, Luo, Cancan, Luo, Yanan, Zang, Yuanyuan, Zeng, Hanyu, Guo, Yinghao, Xu
• Format: Article
• Language: English
• Subjects: Antioxidant peptides; Crocodile; Molecular docking; Myofibrillar protein
• ISSN: 0963-9969
• DOI: 10.1016/j.foodres.2025.115789

Myofibrillar protein (MP) was extracted from farmed crocodile (Crocodylus siamensis) meat, and three proteases (papaine, neutral protease, and bromelain) were used to hydrolyze MP. The hydrolysates were separated and purified by size exclusion chromatography, and the antioxidant activity of each purified component was determined to obtain the highest antioxidant activity component N3. 8 safe and stable peptide sequences were obtained by peptide sequencing of N3 components by LC-MS/MS. Finally, molecular docking technology was used to study the binding mechanism of 8 novel peptides with Keap1 protein, so as to explore the mechanism of the new peptides on the Keap1-Nrf2-ARE signaling pathway. [Display omitted] •8 novel antioxidant peptides were first prepared from Siamese alligator muscle protein.•8 novel antioxidant peptides were screened by bioinformatics analysis.•Binding mechanism of 8 peptides to Keap1 protein was explored through molecular docking. To develop a safe, stable and easily absorbed new antioxidant peptide. The myofibrillar protein hydrolysates of Siamese crocodile meat were prepared and purified, their free radical scavenging and Fe2+ chelating ability were determined. The results showed that isolated component 3 of neutral protease hydrolysate (N3) had the highest antioxidant activity. Subsequently, liquid chromatography-mass spectrometry was applied to appraise the amino acid sequences within the N3 component, and 8 novel antioxidant peptides were screened by bioinformatics analysis, the antioxidant test proved that all 8 synthetic peptides had certain antioxidant activity. Among them, there was no significant difference in the DPPH radical scavenging capacity of GWDK, LWDK, ERWP, LGWK and LWAK (P > 0.05), which were higher than that of DFRDY and WYRDD (P  0.05), but remarkably stronger than that of the other 6 peptides (P