45 - Self-association, conformational ordering and gelation of pustulan, (1®6)-b-D-glucan

Nicholas J Stam^1,2, stamnj@gmail.com, Arthur J Stipanovic¹, David J Kiemle¹. (1) Department of Chemistry, State University of New York, College of Environmental Science and Forestry, Syracuse, NY 13210, United States, (2) Department of Biochemistry, Le Moyne College, Syracuse, NY 13214, United States

Deacetylated pustulan, a (1®6)-b-D-glucan harvested from the lichen Umbilicaria papullosa, forms thermoversible gels in water through the development of microcrystalline junction zones. This study sought to determine the conformational ordering steps of the molecule and subsequent intermolecular self association. Viscometric data revealed a slow initial aggregation at which point the gelation rate increased significantly after 8-10 hours. Proton NMR data suggested that crystallite nucleation and growth provided a mechanism for viscosity increase and gelation since peak integrations decreased at the same rate that viscosity increased. Nuclear Overhauser NMR spectra provided evidence for a quick (<1 hour) initial ordering of the chains into a molecular conformation that provides the basis for aggregation and crystallization in the gel.

Sunday, March 21, 2010 05:00 PM
CELL Poster Session (05:00 PM - 07:00 PM)
Location: Hilton San Francisco Union Square
Room: Continental Ballroom 5