In PhD thesis M. Trajkovski studied folding of guanine rich DNA oligonucleotides into G-quadruplexes and investigated their structural characteristics and cation interactions. DNA oligonucleotide d[G2T2G2TGTG2T2G2] also known as “thrombin binding aptamer” (TBA) adopts G-quadruplex structures in the presence of K+ and Na+ ions. With the use of NMR, UV and CD spectroscopy he studied structural features of TBA and its cation interactions in the presence of 15NH4+, K+ and Na+ ions. He also studied interdependence of cation interactions and structural characteristics in d(TG8T)4, which is the longest tetramolecular G-quadruplex studied with high-resolution NMR spectroscopy and is herein used as a model to provide insights into the role of cations in the systems comprised of a number of consecutively stacked G-quartets. With the use of solution state NMR he showed that in the presence of 15NH4+ ions d(TG8T) adopts two G-quadruplex species in which all seven cation binding sites between the eight G-quartets are completely occupied. Potential applications requiring feasibility to control the G-quadruplex fold are hindered due to the fact that the principles that govern the assembly of these tetrahelical structures are mostly unknown. He constructed the DNA oligonucleotide d[G3TG3T4G3T3G3] in order to design a unimolecular G-quadruplex with unprecedented folding topology. By the use of NMR spectroscopy he confirmed its folding topology. With the use of NMR spectroscopy and complementary biophysical methods he showed that the oligonucleotide originating from the guanine rich region from the first intron of the N-myc oncogene in the presence of K+, 15NH4+ and Na+ ions adopts G-quadruplex structures. In the presence of K+ ions he observed an equilibrium between monomolecular and dimeric N-myc G-quadruplexes.
D.09 Tutoring for postgraduate students
COBISS.SI-ID: 266538752Symposium with renowned international participation entitled “Trends in biomolecular structure: from chemistry to function” has been organized between October 3 and 5, 2013 in Ljubljana, Slovenia. The program of this international symposium included presentations and critical assessment of recent discoveries in the study of structure and dynamics of biological macromolecules using NMR. Symposium participants presented the results of their latest research in the fields of proteins, oligonucleotides and small molecules as well as their structural studies and application. The symposium gathered in one place the leading scientists who use NMR spectroscopy in their research. The symposium website is available at http://www.nmr.ki.si/trends_2013/.
B.01 Organiser of a scientific meeting
COBISS.SI-ID: 268860160In an invited lecture at the prominent conference of the German, Italian and Slovenian communities in the field of NMR spectroscopy (35th FGMR Discussion Meeting and Joint Conference of the German, Italian and Slovenian Magnetic Resonance Societies), which took place betweem 9th and 14th of September 2013 in Frauenchiemsee, Germany with exceptional international attendance, we presented our latest findings and results on G-quadruplex structural features and their interactions with cations. The lecture received a remarkable response.
B.04 Guest lecture
COBISS.SI-ID: 36984069