Određivanje temperature glavnog faznog prijelaza neutralnih lipida UV/Vis spektroskopijom

master's thesis

• Title (english): Determination of the main phase transition temperature of neutral lipids by UV/Vis spectroscopy
• Author: Jana Munivrana
• Mentor: Danijela Bakarić (mentor)
• Committee member: Adriana Kenđel (predsjednik povjerenstva)
• Committee member: Tajana Begović (član povjerenstva)
• Committee member: Željka Soldin (član povjerenstva)
• Committee member: Tomislav Jednačak (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2022-10-19, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

Lipidi u vodenom mediju tvore liposome, sferične strukture u kojima se slažu u dvosloje. Faza,
odnosno način slaganja lipida u dvosloje, funkcija je temperature. Glavni fazni prijelaz je
prijelaz lipida iz faze gela u fazu fluida i opaža se pri temperaturi mekšanja Tm. Uz razlikovnu
pretražnu kalorimetriju kao rutinsku tehniku određivanja Tm odnedavno se ističe i UV/Vis
spektroskopija. U sklopu ovog rada pripremljene su suspenzije 1,2-dipalmitoil-sn-glicero-3-
fosfokolina (DPPC), 1,2-dipalmitoil-sn-glicero-3-fosfoetanolamina (DPPE), 2-oleil-1-
palmitoil-glicero-3-fosfoetanolamina (POPE) i sfingomijelina (SM) u acetatnom, fosfatnom i
karbonatnom puferu (pH = 4,09; 7,01; 9,19). Razlikovnom pretražnom kalorimetrijom i
temperaturno-ovisnom UV/Vis spektroskopijom određene su vrijednosti Tm lipida te je ispitan
utjecaj pH medija na Tm. Pokazano je da je temperaturno-ovisna UV/Vis spektroskopija
prikladna za određivanje Tm te da promjena pH najviše utječe na DPPE i POPE liposome.

Abstract (english)

Lipids form liposomes in which they arrange into bilayers. The transition of lipids from the gel
to the fluid phase, namely the main phase transition, is observed at the melting temperature Tm.
Alongside differential scanning calorimetry (DSC), a routine technique for Tm determination,
UV/Vis spectroscopy recently stood out. As part of this thesis, suspensions of 1,2-dipalmitoylsn-glycero-3-phosphocholine (DPPC), 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine
(DPPE), 2-oleyl-1-palmitoyl-glycero-3-phosphoethanolamine (POPE) and sphingomyelin
(SM) in three buffers (pH = 4.09; 7.01; 9.19) were prepared. Using DSC and temperaturedependent UV/Vis spectroscopy, Tm of lipids were determined and the influence of pH on Tm
was examined. It was shown that temperature-dependent UV/Vis spectroscopy is suitable for
determining Tm and that DPPE and POPE liposomes are affected by the change in the pH.

• Keywords: DSC; fazni prijelaz; liposomi; UV/Vis spektroskopija
• Keywords (english): DSC; liposomes; phase transition; UV/Vis spectroscopy
• Language: croatian
• URN:NBN: urn:nbn:hr:217:153741
• Project: Number: UIP-2020-02-7669; Title: Model demijelinizacije na molekulskoj skali pri fiziološkim i patološkim uvjetima; Title: Model of demyelination on a molecular scale at physiological and pathological conditions; Acronym: DEMYMOLSCALE; Leader: Danijela Bakarić; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: UIP
• Study programme: Title: Graduate university studies in chemistry; specializations in: Research programme; Course: Research programme; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra kemije (magistar/magistra kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2024-10-19
• Created on: 2022-11-04 10:42:19