Crystal Structure of B-Amylose

Abstract

A fiber specimen of B-amylose was prepared from enzymatically synthesized amylose, which is a purely linear 1,4-linked poly-R-D-glucose. X-ray crystal structure analysis was carried out by using the newly collected intensity data, which was estimated by using imaging plate according to the new procedure. The molecule of B-amylose assumes a left-handed parallel strand double helix, and two double helices pass through a hexagonal unit cell with parameters a ) b ) 18.52 Å, c (fiber axis) ) 10.57 Å, γ ) 120°, and the space group P6 1sC6 2 . A total of 36 water molecules were contained in a unit cell. The conformation of the primary hydroxyl group is gg, and the conformation of the bonds linking two glucose residues, Φ and Ψ, are +84.3 and -135.2°, respectively.

Effect of pulsed electrical fields on the structural properties that affect french fry texture during processing

“…The B-type structure is characterized by a large proportion of long amylopectin branches (Gilbert, Besnard, Reeve, Lambides, & Hasjim, 2013) and fewer short branches (Hizukuri, Takeda, & Yasuda, 1981). water molecules per unit cell (Takahashi, Kumano, & Nishikawa, 2004).…”

Relationship between intrinsic viscosity, thermal and retrogradation properties of amylose and amylopectin

“…Recently, many researchers have reported various properties of amylose such as structural conformation and stability in solvents (Nakanishi et al 1993;Shimada et al 2000;Radosta et al 2001;Tusch et al 2011), conformational transitions (Cheetham & Tao 1997), crystallisation and crystal structure (Takahashi et al 2004;Creek et al 2006;Popov et al 2009;Montesanti et al 2010), amylose complexes (Hulleman et al 1996;Ozcan & Jackson 2002;Nuessli et al 2003;Ciesielski & Tomasik 2004;Cardoso et al 2007;Nishiyama et al 2010), gel microstructure and textural properties (Torres et al 1978;Leloup et al 1992) and amylose gel physical network (Lay & Delmas 1998). Whereas, research on the properties of amylopectin was focused on its structural and retrogradation properties (Manners & Matheson 1981;Manners 1989;Paredes-Lopez et al 1994), crystallinity of amylopectin films and network formation (Putaux et al 2000;Myllarinen et al 2002), and amylopectin complexes (Ciesielski & Tomasik 2004).…”

Characterization Methods for Starch-Based Materials: State of the Art and Perspectives

“…[99,102] A-type crystallites have a monoclinic unit cell [103,104] and B-type crystallites are formed by a hexagonal unit cell which contains a large water channel. [105,106] C-type crystallinity is a mixture of both A-and B-type crystallites, with A-type crystallites typically localized at the granule periphery and B-type closer to the centre. [107] The full distribution function describing Level 3 structure is…”