title: Isolation and characterisation of sericin antifreeze peptides and molecular dynamics modelling of their ice-binding interaction.
abstract: This study aimed to isolate and characterise a novel sericin antifreeze peptide and investigate its ice-binding molecular mechanism. The thermal hysteresis activity of ice-binding sericin peptides (I-SP) was measured and their activity reached as high as 0.94 °C. A P4 fraction, with high hypothermia protective activity and inhibition activity of ice recrystallisation, was obtained from I-SP, and a purified sericin peptide, named SM-AFP, with the sequence of TTSPTNVSTT and a molecular weight of 1009.50 Da was then isolated from the P4 fraction. Treatment of Lactobacillus delbrueckii Subsp. bulgaricus LB340 LYO with 100 μg/ml synthetic SM-AFP led to 1.4-fold increased survival (p < 0.05). Finally, an SM-AFP/ice binding model was constructed and results of molecular dynamics simulation suggested that the binding of SM-AFP with ice and prevention of ice crystal growth could be attributed to hydrogen bond formation, hydrophobic interaction and non-bond interactions. Sericin peptides could be developed into beneficial cryoprotectants and used in frozen food processing.
authors.affiliation: Department of Food Science and Engineering, Bor S. Luh Food Safety Research Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Jinhong
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Food Science and Engineering, Bor S. Luh Food Safety Research Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Yuzhi
authors.initials: Y
authors.lastname: Rong
authors.affiliation: Department of Food Science and Engineering, Bor S. Luh Food Safety Research Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Zhengwu
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Food Science, College of Biological Science and Technology, Fuzhou University, Fuzhou 350002, China.
authors.forename: Yanfu
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Food Science, College of Biological Science and Technology, Fuzhou University, Fuzhou 350002, China. Electronic address: shywang@fzu.edu.cn.
authors.forename: Shaoyun
authors.initials: S
authors.lastname: Wang
authors.affiliation: College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210097, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhao
mesh_terms: D021301:Antifreeze Proteins / Q000737:chemistry*; D006860:Hydrogen Bonding; D007053:Ice / Q000032:analysis*; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D047030:Sericins / Q000737:chemistry*
chemical_list: D021301:Antifreeze Proteins; D007053:Ice; D047030:Sericins
keywords: Antifreeze activity; Ice-binding; Isolation; Molecular dynamic modelling; Sericin peptides