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Morphologies and conformation transition of lentinan in aqueous NaOH solution
Author(s) -
Zhang Xufeng,
Zhang Lina,
Xu Xiaojuan
Publication year - 2004
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.20112
Subject(s) - lentinan , chemistry , aqueous solution , random coil , triple helix , radius of gyration , hydrodynamic radius , intrinsic viscosity , viscometer , crystallography , helix (gastropod) , glucan , optical rotation , dynamic light scattering , polysaccharide , circular dichroism , analytical chemistry (journal) , chromatography , stereochemistry , organic chemistry , viscosity , chemical engineering , polymer , snail , nanoparticle , ecology , engineering , biology , quantum mechanics , micelle , physics
Abstract Molecular morphologies and conformation transition of lentinan, a β‐(1→3)‐ D ‐glucan from Lentinus edodes , were studied in aqueous NaOH solution by atomic force microscopy (AFM), viscometry, multiangle laser light scattering, and optical rotation measurements. The results revealed that lentinan exists as triple‐helical chains and as single random‐coil chains at NaOH concentration lower than 0.05 M and higher than 0.08 M , respectively. Moreover, the dramatic changes in weight‐average molecular weight M w , radius of gyration 〈 s 2 〉 1/2 , intrinsic viscosity [η], as well as specific optical rotation at 589 nm [α] 589 occurred in a narrow range of NaOH concentration between 0.05 and 0.08 M NaOH, indicating that the helix–coil conformation transition of lentinan was carried out more easily than that of native schizophyllan and scleroglucan, and was irreversible. For the first time, we confirmed that the denatured lentinan molecule, which was dissolved in 0.15 M NaOH to be disrupted into single coil chains, could be renatured as triple helical chain by dialyzing against abundant water in the regenerated cellulose tube at ambient temperature (15°C). In view of the AFM image, lentinan in aqueous solution exhibited the linear, circular, and branched species of triple helix compared with native linear schizophyllan or scleroglucan. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004