Structural Characterization of Fungal Carbohydrates

AppRidge has developed extensive expertise in the structural characterization of fungal carbohydrates, especially mannans and glucans, using nuclear magnetic resonance spectroscopy.  These studies enhance structure/property relationships for cell-wall fungal carbohydrates.  

NMR of (1-3,1-6)-ß-Glucans   

AppRidge has accomplished a thorough structural characterization of linear (1-3,1-6)-ß-glucan from Candida glabrata (1) and cyclic (1-3,1-6)-ß-glucan from C. albicans hyphae (2).  From these studies, technology has been developed to enable calculation of the average (1-6)-linked side chain content in terms of chain length and frequency of branching along the main (1-3)-linked polymer backbone chain using the 1D proton NMR spectrum (3).  The molecular weight of a low molecular weight glucan can also be calculated from the 1D proton NMR spectrum (3).   

NMR of Mannans  

There is an extensive published literature on the structural characterization of mannans by NMR.  In these studies, mannans were decomposed into small structural oligomers that are carefully separated into individual oligomers, then individually structurally characterized by 1D and 2D NMR techniques.  AppRidge has collected the results of these studies to develop a more rapid and cost-effective approach for the structural characterization of mannans using 1D and 2D COSY NMR (4).

Selected References: 

(1)  “New Insights into the Structure of (1-3,1-6)-D-ß-Glucan Side Chains in the Candida glabrata Cell Wall,” Douglas W. Lowman, Lara J. West, Daniel W. Bearden, Michael F. Wempe, Trevor D. Power, Harry E. Ensley, Ken Haynes, David L. Williams, Michael D. Kruppa, PloS ONE, 6(11): e27614 (2011) 

(2) "Structural features in Candida albicans hyphal glucan provide a basis for differential innate immune recognition of hyphae versus yeast,"  Lowman, D. W., Greene, R. R., Bearden, D. W., Kruppa, M., Pottier, M., Monteiro, M., Soldatov, D., Ensley, H. E., Cheng, S.-C., Netea, M. G., Williams, D. L.  Novel  J. Biol Chem 289 (6) 3432-43, 2014. 

(3) "Structural characterization of (1-3)-ß-D-glucans isolated from blastospore and hyphal forms of Candida albicans," Douglas W. Lowman, Donald A. Ferguson, and David L. Williams, Carbohydrate Research, 338, 1491-96 (2003)

(4) “Mannan structural complexity is decreased when Candida albicans is cultivated in blood or serum at physiological temperature,” Douglas W. Lowman, Harry E. Ensley, Rachel R. Greene, Kevin J. Knagge, David L. Williams, Michael D. Kruppa, Carbohydrate Research 2011, 346, 2752-2759