Base-pairing of uracil and 2,6-diaminopurine: from cocrystals to photoreactivity
Tomislav Stolar,
Ben K.D. Pearce,
Martin Etter,
Khai-Nghi Truong,
Tea Ostojić,
Andraž Krajnc,
Gregor Mali,
Barbara Rossi,
Krešimir Molčanov,
Ivor Lončarić,
Ernest Meštrović,
Krunoslav Užarević,
Luca Grisanti
Affiliations
Tomislav Stolar
Ruđer Bošković Institute, Bijenička c. 54, 10000 Zagreb, Croatia; Federal Institute for Materials Research and Testing (BAM), Richard-Willstätter-Straße 11, 12489 Berlin, Germany; Corresponding author
Ben K.D. Pearce
Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
Rigaku Europe SE, Hugenottenallee 167, 63263 Neu-Isenburg, Germany
Tea Ostojić
Ruđer Bošković Institute, Bijenička c. 54, 10000 Zagreb, Croatia
Andraž Krajnc
National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
Gregor Mali
National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
Barbara Rossi
Elettra Sincrotrone Trieste, Strada Statale 14 km 163.5, 34149 Trieste, Italy
Krešimir Molčanov
Ruđer Bošković Institute, Bijenička c. 54, 10000 Zagreb, Croatia
Ivor Lončarić
Ruđer Bošković Institute, Bijenička c. 54, 10000 Zagreb, Croatia
Ernest Meštrović
Faculty of Chemical Engineering and Technology, University of Zagreb, Trg Marka Marulića 19, 10000 Zagreb, Croatia; Corresponding author
Krunoslav Užarević
Ruđer Bošković Institute, Bijenička c. 54, 10000 Zagreb, Croatia; Corresponding author
Luca Grisanti
Ruđer Bošković Institute, Bijenička c. 54, 10000 Zagreb, Croatia; National Research Council - Materials Foundry Institute (CNR-IOM) c/o SISSA (International School for Advanced Studies), Via Bonomea 265, 34136 Trieste, Italy; Corresponding author
Summary: We show that the non-canonical nucleobase 2,6-diaminopurine (D) spontaneously base pairs with uracil (U) in water and the solid state without the need to be attached to the ribose-phosphate backbone. Depending on the reaction conditions, D and U assemble in thermodynamically stable hydrated and anhydrated D-U base-paired cocrystals. Under UV irradiation, an aqueous solution of D-U base-pair undergoes photochemical degradation, while a pure aqueous solution of U does not. Our simulations suggest that D may trigger the U photodimerization and show that complementary base-pairing modifies the photochemical properties of nucleobases, which might have implications for prebiotic chemistry.
