The intrinsically disordered protein LEA7 from Arabidopsis thaliana protects the isolated enzyme lactate dehydrogenase and enzymes in a soluble leaf proteome during freezing and drying.

摘要: The accumulation of Late Embryogenesis Abundant (LEA) proteins in plants is associated with tolerance against stresses such as freezing and desiccation. Two main functions have been attributed to LEA proteins: membrane stabilization enzyme protection. We hypothesized previously that LEA7 from Arabidopsis thaliana may stabilize membranes because it interacts liposomes the dry state. Here we show LEA7, contrary this expectation, did not during drying rehydration. Instead, partially preserved activity lactate dehydrogenase (LDH) freezing. Fourier-transform infrared (FTIR) spectroscopy showed no evidence aggregation LDH or rehydrated state under conditions lead complete loss activity. To approximate complex influence intracellular on protective effects a protein convenient in-vitro assay, measured two enzymes (glucose-6-P ADP-glucose pyrophosphorylase) total soluble leaf extract (Arabidopsis proteome, ASP) after rehydration thawing. both these conditions, suggesting its role an protectant vivo. Further FTIR analyses indicated partial reversibility ASP Similarly, was strongly reduced by LEA7. In addition, mixtures sucrose verbascose more than single additives, presumably through H-bonding network sugar glasses.