title: The volume and hydration of the Cryptococcus neoformans polysaccharide capsule.
abstract: We present a new method to measure capsule size in the human fungal pathogen Cryptococcus neoformans that avoids the limitations and biases inherent in India ink measurements. The method is based on the use of gamma-radiation, which efficiently releases the capsule from the cell. By comparing the volume of irradiated and non-irradiated cells, one can accurately estimate the relative size of the capsule per cell. This method was also used to obtain an estimate of the capsule weight and water content. The C. neoformans capsule is a highly hydrated structure in all the conditions measured. However, after capsule enlargement, the amount of capsular polysaccharide significantly increases, suggesting a that capsule growth has a high energy cost for the cell.
authors.affiliation: Albert Einstein College of Medicine, Department of Microbiology and Immunology, Bronx, NY 10461, USA.
authors.forename: Michelle E
authors.initials: ME
authors.lastname: Maxson
authors.forename: Emily
authors.initials: E
authors.lastname: Cook
authors.forename: Arturo
authors.initials: A
authors.lastname: Casadevall
authors.forename: Oscar
authors.initials: O
authors.lastname: Zaragoza
mesh_terms: D003455:Cryptococcus neoformans / Q000166:cytology / Q000378:metabolism* / Q000528:radiation effects; D005720:Gamma Rays; D021621:Imaging, Three-Dimensional; D018613:Microscopy, Confocal; D011134:Polysaccharides / Q000378:metabolism*; D014867:Water / Q000378:metabolism
chemical_list: D011134:Polysaccharides; D014867:Water