Antifreeze Peptides Derived from Silver Carp Parvalbumin: Dual Mechanisms of Ice Inhibition and Membrane Stabilization for Superior Yeast Cryopreservation

This study investigated the cryoprotective effects and mechanisms of antifreeze peptides derived from silver carp parvalbumins (PV-AFPs) in a yeast model, employing a combined experimental and computational approach. Results showed that PV-AFPs significantly enhanced yeast survival rate (9.1-46.8 fold) after 1-3 freeze-thaw cycles, improved intracellular protein preservation, reduced structural damage, and maintained mitochondrial membrane potential (5.3-fold higher retention than control). PV-AFPs also reduced freezable water content, inhibited intracellular ice formation, and depressed the extracellular ice formation temperature from -16.6 to -21.4 °C. Molecular docking and molecular dynamics simulations revealed that PV-AFPs stabilized membrane protein Ehs1p by binding to polar and hydrophobic residues, thereby preserving cell membrane/wall integrity. This study demonstrates, for the first time, the dual cryoprotective mechanism of PV-AFPs, involving ice formation inhibition and cell membrane/wall stabilization. Further validation in real dough systems and clarification of individual peptide contributions remain key objectives for future work.