20.500.12556/RUL-172099 Pomen hidrofobnih interakcij za stabilnost proteinov na primeru jajčnega lizocima The influence of hydrophobic effect on the protein stability in the case study of hen egg white lysozyme V diplomskem delu smo preučevali vpliv hidrofobnega efekta na stabilnost proteinov, in sicer na primeru kokošjega jajčnega lizocima (HEWL). Uporabili smo dve eksperimentalni tehniki: cirkularni dikroizem (CD) in diferenčno dinamičnao kalorimetrijo (DSC), s katerima smo analizirali termično stabilnost lizocima v različnih pogojih – v navadni vodi (H₂O), devterirani vodi (D₂O) ter v prisotnosti različnih soli (NaBr, CaCl₂ in Na₂CO₃). Rezultati so skladni s Hofmeistrovo serijo in termodinamskimi načeli denaturacije proteinov. CD in DSC meritve so pokazale, da so spremembe v sekundarni strukturi in termodinamski parametri (entalpija, entropija, prosta energija) v veliki meri pogojeni s topilom in prisotnimi ioni. Prisotnost devterirane vode je dosledno izboljšala termično stabilnost proteina, kar potrjuje večjo moč hidrofobnih interakcij v primerjavi z navadno vodo. Vpliv ionov pa je odvisen od njihove hidratacijske sposobnosti. In this work, the influence of the hydrophobic effect on protein stability was studied, specifically using hen egg-white lysozyme (HEWL) as a model protein. Two experimental techniques were employed: circular dichroism (CD) and differential scanning calorimetry (DSC), which were used to analyze the thermal stability of lysozyme under various conditions – in regular water (H₂O), deuterated water (D₂O), and in the presence of different salts (NaBr, CaCl₂, and Na₂CO₃). The results are consistent with the Hofmeister series and the thermodynamic principles of protein unfolding. CD and DSC measurements showed that changes in secondary structure and thermodynamic parameters (enthalpy, entropy, free energy) are largely influenced by the solvent and the ions present. The presence of deuterated water consistently increased the thermal stability of the protein, confirming the greater strength of hydrophobic interactions compared to regular water. The influence of ions, on the other hand, depends on their hydration capacity. kokošji jajčni lizocim hidrofobni efekt težka (devterirana) voda termična stabilnost proteinov hidratacija ioni hen egg-white lysozyme hydrophobic effect heavy (deuterated) water thermal stability of proteins hydration ions true false false Slovenski jezik Angleški jezik Diplomsko delo/naloga 2025-09-05 14:10:00 2025-09-05 14:10:06 2025-10-22 13:14:58 0000-00-00 00:00:00 2025 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 25489 254302467 Rajteric_Lara_-_Pomen_hidrofobnih_interakcij_za_stabilnost_proteinov_na_primeru_jajcnega_lizocim.pdf Rajteric_Lara_-_Pomen_hidrofobnih_interakcij_za_stabilnost_proteinov_na_primeru_jajcnega_lizocim.pdf 1 AF210D64514501229371E25313CA977C 3ff157adc7c381a6dbe0f69e36fc7c8fa5563f5b78a64318662892c459d138ca 1d20642b-8a51-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=215877 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0