Ice crystallization under cryogenic cooling in lipid membrane nanoconfined geometry: Time-resolved structural dynamics
Abstract
Time-resolved structural investigations of crystallization of water in lipid/protein/salt mesophases at cryogenic temperatures are significant for comprehension of ice nanocrystal nucleation kinetics in lipid membranous systems and can lead to a better understanding of how to experimentally retard the ice for-mation that obstructs the protein crystal structure determination. Here, we present a time-resolved syn-chrotron microfocus X-ray diffraction (TR-XRD) study based on 40,000 frames that revealed the dynamics of water-to-ice crystallization in a lipid/protein/salt mesophase subjected to cryostream cool -ing at 100 K.
The monoolein/hemoglobin/salt/water system was chosen as a model composition related to protein-loaded lipid cubic phases (LCP) broadly used for the crystallization of proteins. Under confine-ment in the nanoscale geometry, metastable short-living cubic ice (Ic) rapidly crystallized well before the formation of hexagonal ice (Ih).
The detected early nanocrystalline states of water-to-ice transformation in multicomponent systems are relevant to a broad spectrum of technologies and understanding of nat-ural phenomena, including crystallization, physics of water nanoconfinement, and rational design of anti-freezing and cryopreservation systems.(c) 2022 Elsevier Inc. All rights reserved.