Structure and chain conformation of a neutral intracellular heteropolysaccharide from mycelium of Paecilomyces cicadae.
A neutral heteropolysaccharide (PCIPS2) was isolated and purified from mycelium of Paecilomyces cicadae, which was investigated to be mainly composed of D mannose, L rhamnose, 3 O methyl D galactose, D glucose and D galactose with a molar ratio of 47.9:3.1:6.4:0.9:0.8. It had a backbone of 1,4 linked a L Rhap residues and 1,6 linked a D Manp residues with branches at O 3 of a D Manp residues. Its side chain was comprised of minor terminal b D glucose and 1,4 linked a 3 O Me D Galp residues terminated by a D galactose. Furthermore, its chain information on the values of weight average molar mass (Mw) root mean square radius [Formula: see text] hydrodynamic radius (Rh) and intrinsic viscosity [e] for PCIPS2 were analyzed to be 3.09 x 10(4)g/mol, 7.8 nm, 3.6 nm and 8.5 mL/g, respectively. The structural exponent a of 0.57 indicated that PCIPS2 existed as a flexible chain conformation with a coil like structure in 0.1M NaNO3 at 25 degC. In terms of known theory for worm like chains, the model parameters for PCIPS2 were as following: molar mass per unit contour length (ML) 379 nm( 1) persistence length (q) 0.74 nm and hydrodynamic diameter of cylinder (d) 0.82 nm, which were further evidenced by atomic force microscopy (AFM)
Carbohydrate polymers