O-glikozilacija proteina u biljaka

undergraduate thesis

• Title (english): O-glycosylation in plant proteins
• Author: Anita Čarija
• Mentor: Biljana Balen (mentor)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2010, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

O-glikozilacija mucinskog tipa je dobro proučena kod sisavaca, ali ne i kod biljaka. Pročišćene nereducirajuće proteinske (prolaminske) frakcije topljive u alkoholu, dobivene iz sjemenaka riže, proučavane su kako bi se ustanovila prisutnost O-vezanih oligosaharida. Budući da je mala vjerojatnost da su skladišni prolamini O-glikozilirani, prisutnost O-glikozilacije u ekstraktu mogla bi se pripisati ko-ekstrahiranim proteinima, bilo to zbog njihove asociranosti s proteinskim tijelom ili zbog njihove topljivosti. Analize provedene SDS-PAGE i MS metodama otkrile su proteinske obitelji od 14 i 16 kDa prisutne u pročišćenim prolaminskim frakcijama koje su se vezale za lektine aglutinina iz kikirikija (PNA), lektine iz biljke Vicia villosa (VVL) i Jacalin, što ukazuje na prisutnost O-vezanih saharida. Otkriven je i udio ugljikohidrata koji sadrţe O-vezan GlcNAc motiv. Protein blotting s anti-O-GlcNAc protutijelom je bio pozitivan za subpopulaciju frakcije proteina od 14 kDa, ali hot capping eksperiment je bio negativan. Stoga, GlcNAc ogranak najvjerojatnije nije teminalan. Obilježavanje fluorescentnim bojama i analize HPLC pokazale su vrh koji sadrži Gal-β-(1→3)-GalNAc. O-glikozilacije mogla bi pridonositi proteinskoj funkcionalnosti ili regulaciji, ali daljnja istraživanja su potrebna kako bi se identificirali specifični proteini koji imaju ovakve modifikacije.

Abstract (english)

Mucin-type O-glycosylation has been well characterized in mammalian systems but not in plants. The purified alcohol-soluble, non-reduced protein (prolamin) fraction from rice seed was investigated for the occurrence of O-linked oligosaccharides. As it is unlikely that storage prolamins are O-glycosylated, any O-gycosylation present in the extract could be attributable to co-extracted proteins, whether because of their association with the protein body or solubility. SDS-PAGE and MS analyses revealed 14 and 16 kDa protein families present in purified prolamin fractions that bound to the lectins peanut agglutinin (PNA), Vicia villosa lectin (VVL) and Jacalin, indicative of the presence of O-linked saccharides. A GlcNAc-containing O-linked carbohydrate moiety was discovered. Protein blotting with anti-O-GlcNAc antibody was positive in a subpopulation of the 14 kDa protein fraction, but a hot capping experiment was negative. Therefore, the GlcNAc residue is unlikely to be terminal. Fluorescent labeling and HPLC analysis demonstrated a peak consistent with Gal-β-(1→3)-GalNAc, with similar MS/MS fragmentation. O-glycosylation may contribute towards protein funcionality or regulation but further investigation is required to identify the specific proteins with these modifications.

• Keywords: O-glikozilacija; biljni proteini
• Keywords (english): O-glycosylation; plant proteins
• Language: croatian
• URN:NBN: urn:nbn:hr:217:473679
• Study programme: Title: Molecular Biology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) molekularne biologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) molekularne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-04-04 09:03:31