Strukturne značilnosti in vloga G-kvadrupleksov v DNA pri človeku

Mulić, Ajša (author), Prislan, Iztok (mentor)

Namen diplomskega dela je bil preučiti nekanonične strukture DNA, predvsem G-kvadruplekse (G4), ter njihov pomen v človeškem genomu. V teoretičnem delu smo predstavili njihovo vlogo pri uravnavanju izražanja genov, replikaciji DNA in ohranjanju genomske stabilnosti ter njihov potencial kot tarč za razvoj novih protitumorskih učinkovin. V eksperimentalnem delu smo proučevali vpliv kalijevih (K⁺) in natrijevih (Na⁺) ionov na oligonukleotidni aptamer AS1411, ki tvori G-kvadrupleksno strukturo. Z uporabo metod krožnega dikroizma (CD), UV-Vis spektrofotometrije in diferenčne dinamične kalorimetrije (NanoDSC) smo analizirali njegovo strukturno stabilnost ob prisotnosti monovalentnih kationov kalija in natrija. Rezultati so pokazali, da kalijevi ioni izrazito stabilizirajo G-kvadrupleksno strukturo AS1411, kar se odraža v višji temperaturi prehoda iz zvite v razvito obliko v primerjavi z natrijevimi ioni. Dobljeni rezultati potrjujejo pomemben vpliv ionskega okolja na stabilnost G-kvadrupleksov.

• Language: Slovenian
• Keywords: biotehnologija, DNA, človeška DNA, G-kvadrupleksi
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: BF - Biotechnical Faculty
• Year: 2026
• PID: 20.500.12556/RUL-185917
• COBISS.SI-ID: 288900099
• Publication date in RUL: 23.08.2026

Secondary language

• Language: English
• Title: Structural features and role of G-quadruplexes in human DNA

Abstract

The aim of this bachelor's thesis was to investigate non-canonical DNA structures, with particular emphasis on G-quadruplexes (G4), and their role in the human genome. The theoretical part provides an overview of their involvement in the regulation of gene expression, DNA replication, and the maintenance of genomic stability, as well as their potential as targets for the development of novel anticancer therapeutics. The experimental part investigated the effects of potassium (K⁺) and sodium (Na⁺) ions on the oligonucleotide aptamer AS1411, which adopts a G-quadruplex structure. Circular dichroism (CD) spectroscopy, UV-Vis spectrophotometry, and differential scanning calorimetry (NanoDSC) were used to evaluate its structural stability in the presence of these monovalent cations. The results showed that potassium ions markedly stabilize the G-quadruplex structure of AS1411, as demonstrated by a higher melting temperature compared with sodium ions. These findings confirm the significant influence of the ionic environment on the stability of G-quadruplex structures.

• Keywords: biotechnology, DNA, human DNA, G-quadruplexes