Inhibitory effect of Ginkgo biloba seeds peptides on methylglyoxal-induced glycations

The aim of this study was to investigate the antiglycation activity and mechanism of two identified peptides, Valine-Valine-Phenylalanine-Proline-Glycine-Cysteine-Proline-Glutamic acid (VVFPGCPE) and Serine-Valine-Aspartic acid-Aspartic acid-Proline-Arginine-Threonine-Lysine (SVDDPRTL), from Ginkgo biloba seeds protein hydrolysates. Both VVFPGCPE and SVDDPRTL were efficient in bovine serum albumin (BSA)-methylglyoxal (MGO) model to inhibit BSA glycation, while VVFPGCPE showed higher antiglycation activity than SVDDPRTL. In antioxidant assays, VVFPGCPE scavenged more hydroxyl and super anion radicals, and chelated more Fe2+. Moreover, VVFPGCPE was more efficient in alleviating glycoxidation since it retained higher content of tryp-tophan and reduced dityrosine and kynurenine generation. Compared with SVDDPRTL, VVFPGCPE showed better performance in inhibiting protein aggregation and amyloid-like fibrillation formation. Therefore, VVFPGCPE was selected for further mechanism study. The circular dichroism analysis suggested VVFPGCPE could preserve alpha-helix structure and stabilize protein structure. The MGO trapping assay indicated VVFPGCPE (5 mg/mL) could capture 66.25% MGO within 24 h, and the mass spectrometry revealed VVFPGCPE could trap MGO by forming VVFPGCPE-mono-MGO adducts. Besides, molecular simulations suggested VVFPGCPE could interact with key glycation residues, arginine and lysine residues, of BSA mainly through van der Waals and hydrogen bonds. This study might supply a theoretical basis for the development of VVFPGCPE as an effective antiglycation agent.

Automated summary

The aim of this study was to investigate the antiglycation activity and mechanism of two peptides identified from Ginkgo biloba seeds protein hydrolysates. Both peptides exhibited efficient antiglycation activity, but VVFPGCPE showed higher activity. VVFPGCPE exerted its effects by scavenging free radicals, chelating metal ions, and stabilizing protein structure. This study provides a theoretical basis for the development of VVFPGCPE as an effective antiglycation agent.