8DYK

Room temperature neutron structure of a fluorescent Ag8 cluster templated by a multistranded DNA scaffold

Summary for 8DYK

• Entry DOI: 10.2210/pdb8dyk/pdb
• Related: 6NIZ
• Descriptor: DNA (5'-D(*AP*AP*CP*CP*CP*C)-3'), SILVER ION (3 entities in total)
• Functional Keywords: dna, metal clusters, silver, chromophore
• Biological source: synthetic construct
• Total number of polymer chains: 2
• Total formula weight: 4662.91

Authors

Meilleur, F.,Lieberman, R.L.,Petty, J.T. (deposition date: 2022-08-04, release date: 2023-08-02, Last modification date: 2024-05-22)

Primary citation

David, F.,Setzler, C.,Sorescu, A.,Lieberman, R.L.,Meilleur, F.,Petty, J.T.
Mapping H + in the Nanoscale (A 2 C 4 ) 2 -Ag 8 Fluorophore.
J Phys Chem Lett, 13:11317-11322, 2022

PubMed Abstract: When strands of DNA encapsulate silver clusters, supramolecular optical chromophores develop. However, how a particular structure endows a specific spectrum remains poorly understood. Here, we used neutron diffraction to map protonation in (AC)-Ag, a green-emitting fluorophore with a "Big Dipper" arrangement of silvers. The DNA host has two substructures with distinct protonation patterns. Three cytosines from each strand collectively chelate handle-like array of three silvers, and calorimetry studies suggest Ag cross-links. The twisted cytosines are further joined by hydrogen bonds from fully protonated amines. The adenines and their neighboring cytosine from each strand anchor a dipper-like group of five silvers via their deprotonated endo- and exocyclic nitrogens. Typically, exocyclic amines are strongly basic, so their acidification and deprotonation in (AC)-Ag suggest that silvers perturb the electron distribution in the aromatic nucleobases. The different protonation states in (AC)-Ag suggest that atomic level structures can pinpoint how to control and tune the electronic spectra of these nanoscale chromophores.

PubMed: 36453924
DOI: 10.1021/acs.jpclett.2c03161

Experimental method

NEUTRON DIFFRACTION (2.1 Å)