Identification of Novel Antifreeze Peptides from Takifugu obscurus Skin and Molecular Mechanism in Inhibiting Ice Crystal Growth

Abstract

Foodborne hydrolyzed antifreeze peptides have been widely used in the food industry and the biomedical field. However, the components of hydrolyzed peptides are complex and the molecular mechanism remains unclear. This study focused on identification and mechanism analysis of novel antifreeze peptides from Takifugu obscurus skin by traditional methods and computerassisted techniques. Results showed that three peptides (EGPRAGGAPG, GDAGPSGPAGPTG, and GEAGPAGPAG) possessed cryoprotection via reducing the freezing point and inhibiting ice crystal growth. Molecular docking confirmed that the cryoprotective property was related to peptide structure, especially α-helix, and hydrogen bond sites. Moreover, the antifreeze peptides were double-faces, which controlled ice crystals while affecting the arrangement of surrounding water molecules, thus exhibiting a strong antifreeze activity. This investigation deepens the comprehension of the mechanism of antifreeze peptides at molecular scale, and the novel efficient antifreeze peptides can be developed in antifreeze materials design and applied in food industry.

Coexisting with Ice Crystals: Cryogenic Preservation of Muscle Food─Mechanisms, Challenges, and Cutting-Edge Strategies

“…Antifreeze peptides have a wide range of applications in the world of comestibles due to their economic viability and consistent ice-modulating ability. As evidenced by materials such as pigskin, 130 Takifugu obscurus skins, 18 squid skins, 131 and silver carp skin, researchers have recently become intensely interested in finding food antifreeze peptides. 132 Takifugu obscurus skins were enzymatically hydrolyzed by Yang et al (2023), 18 who meticulously collected the antifreeze peptide components using ice-affinity adsorption equipment.…”

“…As evidenced by materials such as pigskin, 130 Takifugu obscurus skins, 18 squid skins, 131 and silver carp skin, researchers have recently become intensely interested in finding food antifreeze peptides. 132 Takifugu obscurus skins were enzymatically hydrolyzed by Yang et al (2023), 18 who meticulously collected the antifreeze peptide components using ice-affinity adsorption equipment. After purification, these ingredients yielded three distinct cryoprotective peptides, each with a molecular weight >2 kDa.…”

“…(G) Ice-binding mechanisms of three novel antifreeze peptides. Reproduced with permission from ref . Copyright 2023 American Chemical Society.…”

“…Furthermore, ice nuclei at the atomic level are modulated excitingly by naturally occurring antifreeze proteins (AFPs) and ice nucleating proteins (INPs) . The most effective ways to control ice formation entail increasing heat transfer efficiency, as demonstrated by procedures such as ultrasonic-assisted freezing , and liquid nitrogen freezing. , At the same time, intriguing cryoprotective benefits have been seen with natural deep eutectic solvents (NADES), which have strong hydrating properties, and antifreeze peptides, which have a special affinity for ice prisms. Additionally, temperature variations and slow rewarming are the main causes of IR.…”