TY - JOUR
T1 - The elastic properties of the Cryptococcus neoformans capsule
AU - Frases, Susana
AU - Pontes, Bruno
AU - Nimrichter, Leonardo
AU - Rodrigues, Marcio L.
AU - Viana, Nathan B.
AU - Casadevall, Arturo
N1 - Funding Information:
This work was supported by National Institutes of Health awards AI033774, 5R01HL059842, and 2R37AI033142, and by the Programa de Núcleos de Excelência (MCT/PRONEX), the Brazilian agencies Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Instituto do Milênio de Nanociências, Instituto do Milênio de Avanço Global e Integrado da Matemática Brasileira, Fundação de Amparo à Pesquisa do Rio de Janeiro (FAPERJ), and Fundação Universitária José Bonifácio (FUJB).
PY - 2009/8/19
Y1 - 2009/8/19
N2 - Microbial capsules are important for virulence, but their architecture and physical properties are poorly understood. The human pathogenic fungus Cryptococcus neoformans has a large polysaccharide capsule that is necessary for virulence and is the target of protective antibody responses. To study the C. neoformans capsule we developed what we believe is a new approach whereby we probed the capsular elastic properties by applying forces using polystyrene beads manipulated with optical tweezers. This method allowed us to determine the Young's modulus for the capsule in various conditions that affect capsule growth. The results indicate that the Young's modulus of the capsule decreases with its size and increases with the Ca2+ concentration in solution. Also, capsular polysaccharide manifests an unexpected affinity for polystyrene beads, a property that may function in attachment to host cells and environmental structures. Bead probing with optical tweezers provides a new, nondestructive method that may have wide applicability for studying the effects of growth conditions, immune components, and drugs on capsular properties.
AB - Microbial capsules are important for virulence, but their architecture and physical properties are poorly understood. The human pathogenic fungus Cryptococcus neoformans has a large polysaccharide capsule that is necessary for virulence and is the target of protective antibody responses. To study the C. neoformans capsule we developed what we believe is a new approach whereby we probed the capsular elastic properties by applying forces using polystyrene beads manipulated with optical tweezers. This method allowed us to determine the Young's modulus for the capsule in various conditions that affect capsule growth. The results indicate that the Young's modulus of the capsule decreases with its size and increases with the Ca2+ concentration in solution. Also, capsular polysaccharide manifests an unexpected affinity for polystyrene beads, a property that may function in attachment to host cells and environmental structures. Bead probing with optical tweezers provides a new, nondestructive method that may have wide applicability for studying the effects of growth conditions, immune components, and drugs on capsular properties.
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U2 - 10.1016/j.bpj.2009.04.043
DO - 10.1016/j.bpj.2009.04.043
M3 - Article
C2 - 19686640
AN - SCOPUS:69449103310
SN - 0006-3495
VL - 97
SP - 937
EP - 945
JO - Biophysical journal
JF - Biophysical journal
IS - 4
ER -