THE SELF-ASSEMBLY AND LIQUID-CRYSTAL FORMATION OF D(GPGPAPGPG)

d(GpGpApGpG) dissolved in water forms liquid crystalline phases of the cholesteric and hexagonal type. The building blocks of the phases are columnar four-stranded aggregates composed of G quartets. The diamete r of the columnar aggregates is larger and the melting temperature is lower than for homoguanylic derivatives, indicating a distorsion and l oss of stability due to the presence of adenines, which do not form a hydrogen-bonded quartet. The present study shows that, as often observ ed for single crystals, it is possible also in the liquid crystalline phase to construct long columnar aggregates composed of shorter segmen ts of the blunt-end type in a ''closed architecture.'' (C) 1997 John W iley & Sons, Inc.