Uloga disulfidnih mostova u ugradnji Scw4 proteina u staničnu stijenku kvasca Saccharomyces cerevisiae

undergraduate thesis

• Title (english): The role of disulphide bonds in the integration of Scw4 protein in the cell wall of Saccharomyces cerevisiae
• Author: Dora Štefok
• Mentor: Renata Teparić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Chemistry and Biochemistry); (Laboratory for Biochemistry); Zagreb
• Defense date and country: 2017-07-17, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Stanična stijenka kvasca je čvrsta i elastična ekstracelularna struktura građena od polisaharida i proteina. Proteini stijenke međusobno se razlikuju po svojoj funkciji i po načinu ugradnje u staničnu stijenku. Scw4 je protein koji se u stijenku djelomično ugrađuje nekovalentnim, a djelomično kovalentnim vezama. Smatra se da je način kovalentnog vezanja Scw4 u stijenku jednak načinu vezanja proteina PIR porodice, odnosno vezanje esterskom vezom labilnom u alkalnim uvjetima. Prema nekim autorima PIR proteini se u stijenku kvasca ugrađuju disulfidnim mostovima, stoga je u ovom radu ispitano imaju li disulfidni mostovi ulogu u ugradnji kovalentno vezane frakcije Scw4 u stijenku. Osim toga ispitano je ima li β-merkaptoetanol ulogu u ekstrakciji nekovalentno vezane frakcije Scw4. Tretman SDS-om sa ili bez β-merkaptoetanola pokazao je da glavnu ulogu u ekstrakciji nekovalentno vezane frakcije proteina Scw4 ima SDS. Neuspješna ekstrakcija sa β-merkaptoetanolom pokazala je da se Scw4 kovalentno u stijenku ne ugrađuje disulfidnim mostova.

Abstract (english)

The yeast cell wall is firm and flexible extracellular structure constructed of polysaccharide moieties and mannoproteins. Except for their physiological role cell wall proteins differ according to the way they are linked to glucan. It is known that Scw4 is partly bound to the cell wall covalently and partly non-covalently. Covalently linked Scw4 is most probably attached to the cell wall in the same way as PIR proteins, by alkali-labile ester linkage. However, some authors think that PIR proteins are linked to the cell wall by disulphide bonds. Therefore, role of disulphide bonds in the integration of Scw4 in the cell wall was examined in this work. Furthermore, some experiments were conducted to find out if β-mercaptoethanol has a role in the extraction of non-covalently linked Scw4. According to the results, non-covalently linked Scw4 is SDS-extractable regardless of the presence of β-mercaptoethanol which means that the SDS has main role in the extraction of non-covalently linked Scw4. Scw4 is covalently linked most probably by ester linkage because it is NaOH extractable, and unsuccessful extraction with β-mercaptoethanol shows that disulphide bonds doesn't have role in the integration of Scw4 in the cell wall.

• Keywords: disulfidni mostovi; Saccharomyces cerevisiae; Scw4
• Keywords (english): disulphide bonds; Saccharomyces cerevisiae; Scw4
• Language: croatian
• URN:NBN: urn:nbn:hr:159:993309
• Study programme: Title: Biotechnology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-07-19 08:34:04