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

We generated a recombinant 96-residue polypeptide corresponding to a sequence Tyr(176)-Gly(273) 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. (C) 2005 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.