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Translational diffusion coefficient of cycloamylose in aqueous sodium hydroxide
Author(s) -
Nakata Yasushi,
Amitani Keiji,
Norisuye Takashi,
Kitamura Shinichi
Publication year - 2003
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.10393
Subject(s) - chemistry , aqueous solution , amylose , diffusion , excluded volume , radius of gyration , dynamic light scattering , sodium hydroxide , crystallography , hydrodynamic radius , thermodynamics , organic chemistry , polymer , starch , micelle , chemical engineering , physics , nanoparticle , engineering
Seven cyclic (1 → 4)‐α‐ D ‐glucan (cycloamylose) samples ranging in weight‐average molecular weight from 5 × 10 3 to 1.8 × 10 4 and γ‐cyclodextrin have been studied by sedimentation equilibrium in dimethylsulfoxide (at 25°C) and by dynamic light scattering in 0.5 N aqueous sodium hydroxide (at 25°C), a good solvent for linear amylose. The measured translational diffusion coefficients D in the aqueous NaOH agree fairly closely with previous Monte Carlo results for cyclic (1 → 4)‐α‐ D ‐glucan chains with excluded volume, when correction is made for the effects of bead diameter and fluctuating hydrodynamic interaction (HI) on the Kirkwood theory on which the computation of D was based. These D data are also explained almost quantitatively by Yamakawa and Fujii's expression for the associated KP ring (based on the Kratky–Porod wormlike chain) with the molecular parameters for linear amylose if the fluctuating HI and excluded‐volume effects are taken into account. It is concluded that the translational diffusion behavior of cycloamylose in the aqueous NaOH is consistent with the conformational characteristics derived from the conformational energy of maltose and dilute‐solution data for linear amylose. © 2003 Wiley Periodicals, Inc. Biopolymers 69: 508–516, 2003