magistrsko delo
Primož Tič (Author), Jurij Lah (Mentor), Miha Pavšič (Thesis defence commission member), Črtomir Podlipnik (Thesis defence commission member)

Abstract

Intrinzično neurejeni proteini (IDP) so obsežna skupina proteinov, ki so v primerjavi z globularnimi proteini veliko bolj fleksibilni. V to skupino spada tudi antitoksin Phd, ki izhaja iz modula toksin-antitoksin (TA) bakteriofaga P1. Ob vezavi na toksin Doc se neurejena C-domena antitoksina strukturira v α-vijačnico. Prosti toksin Doc v celici inhibira sintezo proteinov in upočasni njen metabolizem, vezava antitoksina pa inhibira njegovo delovanje. Vezava toksina ni edini način, s katerim lahko vplivamo na strukturo proteina Phd. Na njegovo strukturo vplivajo tudi okoliški pogoji. Z uporabo CD-spektrometrije in diferenčne dinamične kalorimetrije (DSC) smo preučevali vpliv koncentracije proteina, koncentracije soli in temperature na strukturo Phd ter ocenili termodinamične parametre, ki spremljajo strukturne pretvorbe. Visoka koncentracija proteina, visoka koncentracija soli in nizka temperatura premaknejo ravnotežje v smeri strukturiranega dimera. Nizka koncentracija proteina, nizka koncentracija soli in visoka temperatura premaknejo ravnotežje v smeri nestrukturiranega monomera. Strukturiranje proteina naredi le-tega termodinamično stabilnejšega. Ugotovitve so pomembne za preučevanje proteina Phd in vitro, saj lahko z okoliškimi pogoji vplivamo na strukturo proteina. Strukturne spremembe zaradi sprememb v temperaturi in koncentraciji soli lahko primerjamo s fiziološko pomembnimi strukturnimi spremembami ob vezavi toksina Doc.

Keywords

intrinzično neurejeni proteini;IDP;antitoksin Phd;struktura antitoksina;okoliški pogoji;CD-spektroskopija;diferenčna dinamična kalorimetrija;DSC;magistrska dela;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher: [P. Tič]
UDC: 577.322(043.2)
COBISS: 36526851 Link will open in a new window
Views: 338
Downloads: 65
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Other data

Secondary language: English
Secondary title: Effect of added salt on the structural stability of Phd antitoxin from the module Phd/Doc of bacteriophage P1
Secondary abstract: Intrinsically disordered proteins (IDPs) represent a big group of proteins, whose structure is more flexible compared to globular proteins. Antitoxin Phd is an IDP and originates from a toxin-antitoxin (TA) module of bacteriophage P1. The binding of antitoxin to toxin Doc inhibits the Doc activity. The disordered C-terminal domain of antitoxin Phd forms an α-helix upon binding. Free toxin Doc inhibits protein synthesis and slows down the metabolism of the cell. Apart from the binding of toxin Doc, other factors, like the environment in which the antitoxin is present, affect its structure. Using CD-spectroscopy and DSC-calorimetry we examined the affects of protein concentration, salt concentration and temperature on the protein structure and evaluated thermodynamic parameters, that accompany structural changes of Phd. High concentrations of protein and salt as well as low temperature move the equilibrium towards a structured dimer. Low concentrations of protein and salt as well as high temperature move the equilibrium towards a disordered monomer. Structuring of the protein increases its thermodynamic stability. These findings are important for future in vitro experiments, because we can change the protein structure with changing the environmental conditions of the solution. The changes in protein structure of Phd, caused by changes in temperature and salt concentration, can be compared with those of physiologically relevant toxin binding.
Secondary keywords: antitoxin Phd structure;environmental conditions;CD-spectroscopy;
Type (COBISS): Master's thesis/paper
Study programme: 1000377
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, smer Biokemija
Pages: 49 str.
ID: 12050956