ABSTRACT
ß-Glucan is a (1â3)-ß-linked glucose polymer with (1â6)-ß-linked side chains and a major component of fungal cell walls. ß-Glucans provide structural integrity to the fungal cell wall. The nature of the (1-6)-ß-linked side chain structure of fungal (1â3,1â6)-ß-D-glucans has been very difficult to elucidate. Herein, we report the first detailed structural characterization of the (1â6)-ß-linked side chains of Candida glabrata using high-field NMR. The (1â6)-ß-linked side chains have an average length of 4 to 5 repeat units spaced every 21 repeat units along the (1â3)-linked polymer backbone. Computer modeling suggests that the side chains have a bent curve structure that allows for a flexible interconnection with parallel (1â3)-ß-D-glucan polymers, and/or as a point of attachment for proteins. Based on these observations we propose new approaches to how (1â6)-ß-linked side chains interconnect with neighboring glucan polymers in a manner that maximizes fungal cell wall strength, while also allowing for flexibility, or plasticity.
Subject(s)
Candida glabrata/chemistry , Cell Wall/chemistry , beta-Glucans/chemistry , Magnetic Resonance SpectroscopyABSTRACT
New unsymmetrical S/O 1,1'-disubstituted ferrocenediyl ethers and hydroxides have been synthesised. The coordination chemistry of 1-(methylsulfanyl)-1'-(methoxy)ferrocene has been investigated with palladium(II) and platinum(II) precursors. With palladium(II), a bis-mu-chloro-bridged dimeric complex was obtained with the ligand bound solely through the thioether donor group. With platinum(II), a bis-ligand trans-sulfur ligated complex was obtained and structurally characterised.