Sekundarne strukture DNA v topilih z različno dielektrično konstanto

diplomsko delo

Luka Krmpotić (Author), Janez Plavec (Mentor)

Abstract

V celicah nastajajo brezmembranski organeli, ki predstavljajo ločeno tekočinsko fazo, sestavljeno iz proteinskih verig. Ta okolja so po dielektričnosti podobna organskim topilom, kot sta acetonitril in DMSO. V teh organelih se dvojna vijačnica DNA lahko razvije, strukture enoverižnih nukleinskih kislin pa se stabilizirajo. Z mešanicami topil acetonitril/voda in DMSO/voda smo posnemali dielektričnost okolja znotraj brezmembranskih organelov in opazovali vpliv na sekundarno strukturo DNA. Uporabili smo 17 baznih parov dolge komplementarne DNA verige. Z NMR spektroskopijo smo opazovali vpliv naraščajočega deleža organskih topil na vodikove vezi znotraj dvojne vijačnice DNA. Pokazali smo, da tako DMSO kot acetonitril destabilizirata dvojno vijačnico DNA. DMSO razvije dvojno vijačnico DNA pri nižjih volumskih deležih kot acetonitril. Pri 50% volumskem deležu DMSO v vodi komplementarni 17-merni verigi DNA še interagirajo, a niso več zvitev stabilno dvojno vijačnico. V 50% volumskem deležu acetonitrila v vodi se DNA še zvije v dvojno vijačnico, medtem ko pri 75% deležu ni več stabilnih interakcij med verigami. Pokazali smo, da so v mešanici DMSO/voda bazni pari G-C stabilnejši od baznih parov A-T. Destabilizacija strukture DNA ni povezana z dielektričnim koeficientom mešanic topil DMSO/voda ali acetonitril/voda, zato sklepamo, da ključno vlogo za stabilnost struktur v modelnem sistemu odigrajo drugi dejavniki.

Keywords

DNA;deoksiribonukleinska kislina;stabilizacija DNA;dielektrična konstanta;dimetilsulfoksid;DMSO;acetonitril;brezmembranski organeli;diplomska dela;

Data

Language:	Slovenian
Year of publishing:	2019
Typology:	2.11 - Undergraduate Thesis
Organization:	UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher:	[L. Krmpotić]
UDC:	577.2(043.2)
COBISS:	1538485187
Views:	791
Downloads:	187
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Secondary structures of DNA in solvents with different dielectric constants
Secondary abstract:	Cells form membraneless organelles, which definea separate liquid phase, made out of protein chains. These regions are by their dielectric constant similar to organic solvents such as acetonitrile and DMSO. In these organelles DNA double helix can unwind, while structures from single-stranded nucleic acids become stabilized. In this work we used organic solvents to mimic the dielectricity of environment inside membraneless organelles and observed the effect on DNA secondary structure. We used 17-mer complementary DNA chains. NMR spectroscopy was used to observe the effect on hydrogen bonds within the DNA double helix. We showed that both DMSO and acetonitrile destabilize DNA double helix. DMSO unfolds the DNA double helix at lower volumetric percentage in comparison to acetonitrile. In 50% (v/v) DMSO/water, complementary 17-mer DNA chains still interact, but are not folded into a stable DNA double helix. In 50% (v/v) acetonitrile/water DNA still folds into a double helix, while at 75% there are no stable interactions between the strands. We confirmed that in DMSO/water mixture G-C base pairs are more stable than A-T base pairs. Dielectricity is not the reason for DNA destabilizationin DMSO/water or acetonitrile/water mixtures, key factor for DNA stability in our model system must be found elsewhere.
Secondary keywords:	DNA;dielectric constant;DMSO;acetonitrile;
Type (COBISS):	Bachelor thesis/paper
Study programme:	1000371
Embargo end date (OpenAIRE):	1970-01-01
Thesis comment:	Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, UNI Biokemija
Pages:	32 str.
ID:	11270677