Amylose local conformation

We also observe a negative band at 190 nm in the solution spectrum of pullulan (Table II), but at much reduced intensity relative to amylose. We take this band to originate in the same local conformation responsible for the low energy dichroism in amylose. The intensity, however, is modified by the presence of l->6 linkages between repeating sequences of maltotriose. 

Convergent energy minimization in force-field calculations, carried out initially on a- and /3-D-glucopyranose, has been used to predict the conformations of /3-maltose and cellobiose. ° The four conformations predicted for the former were close to those found in Z-ray structures and n.m.r. experiments, and there was a good correlation with the irregularities known to be present in amylose conformation. There were six local minima identified for cellobiose, the two lowest of which corresponded to the conformations found in X-ray structures. 

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