Antonio Martinez-Richa - DETERMINATION OF MOLECULAR SIZE OF O-(2-HYDROXYETHYL)CELLULOSE (HEC) AND ITS RELATIONSHIP TO THE MECHANISM OF ENZYMATIC HYDROLYSIS BY CELLULASES

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      Publication Details (including relevant citation   information):

      Antonio Martínez-Richa,  Carbohydrate   Polymers, 87 3 2129-2136 (2012)

      Abstract:

      Z-average root mean square end-to-end distance   <ro2>z1/2 and   radius of gyration   <so2>z1/2 for   13 samples of O-(2-hydroxyethyl)cellulose (HEC) of different   molecular weights were derived from Gel Permeation Chromatography   and intrinsic viscosity measurements with water as a solvent. At   40° C and pH = 4.5, contraction of chain dimensions is observed,   compared with the sizes observed under neutral conditions at room   temperature. The effect is lower for samples with higher   molecular weights. Values of   <ro2>40/DPz  also indicate that chain flexibility increases at higher   temperature and acidic conditions. From the analysis of molecular   weight dependence of <so2>   z1/2, Flory exponent u was derived at 40° C   and pH = 4.5. A value of u = 0.70 ± 0.02 was recorded, which   indicates that a relatively stiff chain is present under these   conditions. Finally, different equations to calculate persistence   length Lp were evaluated. Values in the range of   260-400 Ǻ were derived for persistence length. Implications of   chain conformation in the enzymatic action of cellulases are also   discussed.

      Address (URL): http://www.sciencedirect.com/science/article/pii/S0144861711009453