title: Increased duplex stabilization in porphyrin-LNA zipper arrays with structure dependent exciton coupling.
abstract: Porphyrins were attached to LNA uridine building blocks via rigid 5-acetylene or more flexible propargyl-amide linkers and incorporated into DNA strands. The systems show a greatly increased thermodynamic stability when using as little as three porphyrins in a zipper arrangement. Thermodynamic analysis reveals clustering of the strands into more ordered duplexes with both greater negative ΔΔS and ΔΔH values, and less ordered duplexes with small positive ΔΔS differences, depending on the combination of linkers used. The exciton coupling between the porphyrins is dependent on the flanking DNA sequence in the single stranded form, and on the nature of the linker between the nucleobase and the porphyrin in the double stranded form; it is, however, also strongly influenced by intermolecular interactions. This system is suitable for the formation of stable helical chromophore arrays with sequence and structure dependent exciton coupling.
authors.affiliation: School of Chemistry and Institute for Life Sciences, University of Southampton, Highfield, Southampton, SO17 1BJ, UK. est@soton.ac.uk.
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Singleton
authors.forename: Rohanah
authors.initials: R
authors.lastname: Hussain
authors.forename: Giuliano
authors.initials: G
authors.lastname: Siligardi
authors.forename: Pawan
authors.initials: P
authors.lastname: Kumar
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Hrdlicka
authors.forename: Nina
authors.initials: N
authors.lastname: Berova
authors.forename: Eugen
authors.initials: E
authors.lastname: Stulz
mesh_terms: D002942:Circular Dichroism; D015394:Molecular Structure; D009841:Oligonucleotides / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D011166:Porphyrins / Q000737:chemistry*; D013816:Thermodynamics; D015032:Zinc / Q000737:chemistry
chemical_list: D009841:Oligonucleotides; D009942:Organometallic Compounds; D011166:Porphyrins; C477371:locked nucleic acid; D015032:Zinc