An Amylose Antiparallel Double Helix at Atomic Resolution
Abstract
In the crystal structure of the polyiodide complex (p-nitrophenyl-α -maltohexaose2). Ba(I3)2\ \cdot 22H2O, the maltohexaose units form an antiparallel, left-handed double helix with O-2 \cdots O-3 and O-6 \cdots O-6 hydrogen bonding and a central cavity that encloses two triiodide units. This structure contrasts with the parallel, left-handed double helix with no central cavity proposed for the A- and B-starch helix and the left-handed single helix in V-amylose and may be relevant for the stabilization of glycogen structure.
- Publication:
-
Science
- Pub Date:
- October 1987
- DOI:
- 10.1126/science.238.4824.205
- Bibcode:
- 1987Sci...238..205H