Calcium Involved Directional Organization of Polymer Chains in Polyester Nanogranules in Bacterial Cells.

ABSTRACT: Soil bacteria accumulate polyesters (typically poly([R]-3-hydroxybutyrate (PHB), in which one end of the chain terminates with a carboxyl group) in the form of hydrated, amorphous nanogranules in cells. However, it is not clear what drives the structure of these biomaterials inside bacterial cells. Here, we determined that calcium guides intracellular formation of PHB nanogranules. Our systematic study using the surface zeta potential measurement and the carboxyl-specific SYTO-62 dye binding assay showed that the terminal carboxyl is not exposed to the granule surface but is buried inside native "unit-granules" comprising the mature granule. Extracellular Ca²⁺ was found to mediate the formation of these PHB unit-granules, with uptaken Ca²⁺ stored inside the granules.

SUBMITTER: Tian B 

PROVIDER: S-EPMC6401383 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature