Calcium-Binding Generates the Semi-Clathrate Waters on a Type II Antifreeze Protein to Adsorb onto an Ice Crystal Surface.

ABSTRACT: Hydration is crucial for a function and a ligand recognition of a protein. The hydration shell constructed on an antifreeze protein (AFP) contains many organized waters, through which AFP is thought to bind to specific ice crystal planes. For a Ca2+-dependent species of AFP, however, it has not been clarified how 1 mol of Ca2+-binding is related with the hydration and the ice-binding ability. Here we determined the X-ray crystal structure of a Ca2+-dependent AFP (jsAFP) from Japanese smelt, Hypomesus nipponensis, in both Ca2+-bound and -free states. Their overall structures were closely similar (Root mean square deviation (RMSD) of Cα = 0.31 Å), while they exhibited a significant difference around their Ca2+-binding site. Firstly, the side-chains of four of the five Ca2+-binding residues (

SUBMITTER: Arai T 

PROVIDER: S-EPMC6572318 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature