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    Can dietary fibre help provide safer food products for sufferers of gluten intolerance? A well-established biophysical probe may help towards providing an answer
    (Bmc, 2012) Kök, Muhammed Şamil; Gillis, Richard; Ang, Shirley; Lafond, David; Tatham, Arthur S.
    Gluten intolerance is a condition which affects an increasing percentage of the world's population and for which the only current treatment is a restrictive gluten free diet. However could the inclusion of a particular polysaccharide, or blends of different types, help with the provision of 'safer' foods for those individuals who suffer from this condition? We review the current knowledge on the prevalence, clinical symptoms and treatment of gluten intolerance, and the use and properties of the allergens responsible. We consider the potential for dietary fibre polysaccharides to sequester peptides that are responsible for activation of the disease in susceptible individuals, and consider the potential of co-sedimentation in the analytical ultracentrifuge as a molecular probe for finding interactions strong enough to be considered as useful.
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    A novel global hydrodynamic analysis of the molecular flexibility of the dietary fibre polysaccharide konjac glucomannan
    (2009) Kök, Mehmet Şamil; Abdelhameed A.S.; Ang, Shirley; Morris, Gordon A.; Harding, Stephen E.
    Konjac glucomannans have been widely considered in health food products although their hydrodynamic properties have been poorly understood. The weight-average molecular weight (Mw); sedimentation coefficient (s020,w) and intrinsic viscosities ([?]) have been estimated for five different preparations. The decrease in both intrinsic viscosity and sedimentation coefficient with molecular weight enables the estimation of molecular flexibility in terms of persistence length (Lp) using the traditional Bohdanecky-Bushin and Yamakawa-Fujii analyses for intrinsic viscosity and sedimentation data respectively. However, this requires an assumption of the mass per unit length ML. Advantage can now be taken of a recent development in data interpretation which allows the estimation of Lp from combined intrinsic viscosity and sedimentation coefficient data and also an estimate for ML. Using this "global" procedure an estimate of (13 ± 1) nm is found for Lp and a value of (330 ± 10) g mol-1 nm-1 for ML.. The value for Lp suggests a molecule of considerable flexibility, comparable to galactomannans (Lp ? 8-10 nm) but not as flexible as pullulan (Lp ? 1-2 nm). © 2009 Elsevier Ltd. All rights reserved.
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    Structure and heterogeneity of gliadin: a hydrodynamic evaluation
    (Springer, 2010) Ang, Shirley; Kogulanathan, Jana; Morris, Gordon A.; Kök, Mehmet Şamil; Shewry, Peter R.
    A study of the heterogeneity and conformation in solution [in 70% (v/v) aq. ethanol] of gliadin proteins from wheat was undertaken based upon sedimentation velocity in the analytical ultracentrifuge, analysis of the distribution coefficients and ellipsoidal axial ratios assuming quasi-rigid particles, allowing for a range of plausible time-averaged hydration values. All classical fractions (alpha, gamma, omega(slow), omega(fast)) show three clearly resolved components. Based on the weight-average sedimentation coefficient for each fraction and a weight-average molecular weight from sedimentation equilibrium and/or cDNA sequence analysis, all the proteins are extended molecules with axial ratios ranging from similar to 10 to 30 with alpha appearing the most extended and gamma the least.