A part of ice nucleation protein exhibits the ice‐binding ability

Abstract

We generated a recombinant 96‐residue polypeptide corresponding to a sequence Tyr¹⁷⁶–Gly²⁷³ of ice nucleation protein from Pseudomonas syringae (denoted INP96). INP96 exhibited an ability to shape an ice crystal, whose morphology is highly similar to the hexagonal‐bipyramid generally identified for antifreeze protein. INP96 also showed a non‐linear, concentration‐dependent retardation of ice growth. Additionally, circular dichroism and NMR measurements suggested a local structural construction in INP96, which undergoes irreversible thermal denaturation. These data imply that a part of INP constructs a unique structure so as to interact with the ice crystal surfaces.