Molecular weight, structure and shape of oat (1 to 3),(1 to 4)-beta-D-glucan fractions obtained by enzymatic degradation with (1 to 4)-beta-D-glucan 4-glucanohydrolase from Trichoderma reesei
2001
Roubroeks, J.P. | Andersson, R. | Mastromauro, D.I. | Christensen, B.E. | Aman, P.
Oat beta-glucan was partially degraded with (1 leads to 4)-beta-D-glucan 4-glucanohydrolase for different periods of time. Weight average molecular weight and weight average intrinsic viscosity were obtained from SEC-RI-RALLS-Visc and ranged from 2200 to 213,900 g/mol and 7 to 316 ml/g, respectively. The viscosity equation determined [mean eta]w = 1.06 x 10(-2) mean M(w)0.86 indicated an extended random coil conformation. When the coil was modelled as a worm-like chain a persistent length of 3.65 nm was obtained. The hydrolysis products identified after extensive degradation were glucose, cellobiose, laminaribiose, 4-O-beta-laminaribiosyl D-glucose, 4-O-beta-laminaribiosyl D-cellobiose and 3-O-beta-cellobiosyl D-cellobiose showing that other enzyme activities were present. The depolymerization kinetics suggested that longer sequences of consecutive (1 leads to 4)-linkages represent fast hydrolysable sites and the presence of higher relative proportions of (1 leads to 3)-linkages restricts the affinity of the enzyme.
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