High-speed cryo-microscopy reveals that ice-nucleating proteins of <i>Pseudomonas syringae</i> trigger freezing at hydrophobic interfaces.

ABSTRACT: Ice-nucleating proteins (INpro) trigger the freezing of supercooled water droplets relevant to atmospheric, biological, and technological applications. The high ice nucleation activity of INpro isolated from the bacteria Pseudomonas syringae could be linked to the aggregation of proteins at the bacterial membrane or at the air-water interface (AWI) of droplets. Here, we imaged freezing onsets, providing direct evidence of these proposed mechanisms. High-speed cryo-microscopy identified the onset location of freezing in droplets between two protein-repellent glass slides. INpro from sterilized P. syringae (Snomax) statistically favored nucleation at the AWI of the droplets. Removing cellular fragments by filtration or adding surfactants increased the frequency of nucleation ev

SUBMITTER: Bieber P 

PROVIDER: S-EPMC11221516 | biostudies-literature | 2024 Jul

REPOSITORIES: biostudies-literature