Exploring the periodic table with supramolecular G-quadruplexes



Our latest article just came out on the web: Tuning supramolecular G-quadruplexes with mono- and divalent cations (Mariana Martín-Hidalgo, Marilyn García-Arriaga, Fernando González, José M. Rivera,  Supramolecular Chemistry, DOI: 10.1080/10610278.2014.924626) In it we describe a series of systematic studies of the effect of a series of cations on the structure and other properties of supramolecular G-quadruplexes. You can download a free (!) copy of the article here, but you better hurry as this is a limited time offer available only to the first 50 people to take advantage of it. If, however, you are not one of the “50 lucky winners”, don’t despair, you can still get a copy article by simply leaving a request in the comments. In the meantime, here’s the abstract:

Supramolecular G-quadruplexes (SGQs) are formed via the cation promoted self-assembly of guanine derivatives into stacks of planar hydrogen-bonded tetramers. Here, we present results on the formation of SGQs made from the 8-(m-acetylphenyl)-2′-deoxyguanosine (mAGi) derivative in the presence of various mono- and divalent cations. NMR and HR ESI-MS data indicate that varying the cation can efficiently tune the molecularity, the fidelity and stability (thermal and kinetic) of the resulting SGQs. The results show that, parallel to the previously reported potassium-templated hexadecamer (mAGi16·3K+), Na+, Rb+and NH4+ also promote the formation of similar supramolecules with high fidelity and molecularity. In contrast, the divalent cations Pb2+, Sr2+ and Ba2+ template the formation of octamers (mAGi8), with the latter two inducing higher thermal stabilities. Molecular dynamics simulations for the hexadecamers containing monovalent cations enabled critical insights that help explain the experimental observations.


The phoenix finally rises from the ashes…


Every research paper is special and it’s the source of great satisfaction when it finally gets published. Seeing our latest article “A Photoresponsive Supramolecular G-Quadruplex” finally published is particularly satisfying because of the long arduous road to publication. Our internal code name for this manuscript was “Phoenix” because of the parallel between the mythical beast (burning down and raising from the ashes) and the supramolecule described in the article, which is destroyed after photoirradiation and eventually leads to a new (heteromeric) supramolecule to rise from the ashes. What we didn’t know the first time we submitted this work for publication was that the manuscript would ended up being “burned down to ashes” by the referees at multiple journals before finally raising for good. The whole process was very humbling and tested our character, but in the end, the final product was a much refined piece of work for which we should be proud of. And now, to continue writing with the hope that our next submissions don’t have to travel such a rough path.