Exploration of the active site of β4GalT7 – Synthesis of substrates and inhibitors
(2017)- Abstract
- β-1,4-Galactosyltransferase 7 (β4GalT7) is a key enzyme in the biosynthesis of proteoglycans (PGs) and glycosaminoglycan (GAG) chains, which are important macromolecules involved in many biological processes such as cell growth and cell signaling as well as in cancer pathobiology and viral and bacterial infections. Despite its pivotal role, much is still unknown regarding the specific structure of GAGs and how the structure affects its functions. GAG synthesis can be regulated by xylosides acting on β4GalT7 as either substrates or inhibitors. In an effort to find efficient substrates and inhibitors of β4GalT7, which would be valuable tools applicable in GAG research, we set out to investigate the active site of β4GalT7 by synthesizing and... (More)
- β-1,4-Galactosyltransferase 7 (β4GalT7) is a key enzyme in the biosynthesis of proteoglycans (PGs) and glycosaminoglycan (GAG) chains, which are important macromolecules involved in many biological processes such as cell growth and cell signaling as well as in cancer pathobiology and viral and bacterial infections. Despite its pivotal role, much is still unknown regarding the specific structure of GAGs and how the structure affects its functions. GAG synthesis can be regulated by xylosides acting on β4GalT7 as either substrates or inhibitors. In an effort to find efficient substrates and inhibitors of β4GalT7, which would be valuable tools applicable in GAG research, we set out to investigate the active site of β4GalT7 by synthesizing and examining xylosides and xyloside analogs with modifications in the xylose moiety, the endocyclic and exocyclic positions, as well as the aglycon. The overarching aim with these investigations was to pinpoint the requirements of efficient substrates and efficient inhibitors. The synthesized compounds were evaluated in a β4GalT7 assay in combination with molecular docking simulations and conformational analysis by NMR spectroscopy. We found that efficient substrates are formed when keeping the xylose moiety unmodified, but exchanging the endocyclic and/or exocyclic oxygen atoms for sulfur, as well as connecting the xyloside to an aglycon consisting of a fused aromatic system, preferably separated from the xylose part by a short oligoethylene glycol spacer. These structural features can not directly be transferred to a xyloside analog possessing inhibitory activity to gain efficient inhibitors of β4GalT7. (Less)
- Abstract (Swedish)
- Ytan av alla celler är dekorerad med kolhydrater som står för mycket av den information en cell överför till omgivande celler. Många av kolhydraterna tillhör en föreningsklass som kallas proteoglykaner som består av ett protein sammanbundet med en eller flera långa kolhydratkedjor. Dessa kolhydratkedjor kallas glykosaminoglykaner och är bundna till proteinet via kolhydraten xylos. Än så länge har vi bara en vag aning om sambanden mellan strukturen hos glykosaminoglykanerna och den information de överför. Denna avhandling handlar om att skapa verktyg som kan ge oss insikter i hur glykosaminoglykanerna bildas.
Xylosider, det vill säga molekyler baserade på xylos kopplat till en annan molekyl – en aglykon, kan gå in i celler och starta... (More) - Ytan av alla celler är dekorerad med kolhydrater som står för mycket av den information en cell överför till omgivande celler. Många av kolhydraterna tillhör en föreningsklass som kallas proteoglykaner som består av ett protein sammanbundet med en eller flera långa kolhydratkedjor. Dessa kolhydratkedjor kallas glykosaminoglykaner och är bundna till proteinet via kolhydraten xylos. Än så länge har vi bara en vag aning om sambanden mellan strukturen hos glykosaminoglykanerna och den information de överför. Denna avhandling handlar om att skapa verktyg som kan ge oss insikter i hur glykosaminoglykanerna bildas.
Xylosider, det vill säga molekyler baserade på xylos kopplat till en annan molekyl – en aglykon, kan gå in i celler och starta eller blockera bildandet av glykosaminoglykaner genom att efterlikna det naturliga substratet för ett visst enzym – β4GalT7. För att öka förståelsen för hur en xylosid ska se ut för att vara ett bra substrat eller en bra hämmare för β4GalT7 har vi syntetiserat och testat aktiviteten av olika xylosider.
Vi har valt att systematiskt undersöka tre olika delar av xylosidmolekylerna - själva kolhydraten, kopplingen och aglykonen. Vi har hittat ett antal nya molekyler som fungerar som bra substrat för β4GalT7 och vi har också hittat substanser som fungerar som hämmare.
Resultaten i den här avhandlingen lägger en grund för vilka strukturelement som kan inkorporeras i xylosider för att ge effektiva substrat samt grundläggande krav för en hämmare.
(Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/c9518749-4ded-4245-bad3-3ea9ec1368db
- author
- Thorsheim, Karin LU
- supervisor
-
- Ulf Ellervik LU
- Sophie Manner LU
- opponent
-
- Associate Professor Sandström, Anja, Uppsala University, Department of Medicinal Chemistry
- organization
- publishing date
- 2017-08
- type
- Thesis
- publication status
- published
- subject
- keywords
- Xylosides, β4GalT7, β-1,4-galactosyltransferase 7, glycosaminoglycan, synthesis
- pages
- 226 pages
- publisher
- Lund University, Faculty of Science, Department of Chemistry
- defense location
- Lecture hall A, Center for chemistry and chemical engineering, Naturvetarvägen 14, Lund
- defense date
- 2017-09-15 9:00:00
- ISBN
- 978-91-7422-535-8
- language
- English
- LU publication?
- yes
- id
- c9518749-4ded-4245-bad3-3ea9ec1368db
- date added to LUP
- 2017-08-22 09:38:37
- date last changed
- 2018-11-21 21:33:59
@phdthesis{c9518749-4ded-4245-bad3-3ea9ec1368db,
abstract = {{β-1,4-Galactosyltransferase 7 (β4GalT7) is a key enzyme in the biosynthesis of proteoglycans (PGs) and glycosaminoglycan (GAG) chains, which are important macromolecules involved in many biological processes such as cell growth and cell signaling as well as in cancer pathobiology and viral and bacterial infections. Despite its pivotal role, much is still unknown regarding the specific structure of GAGs and how the structure affects its functions. GAG synthesis can be regulated by xylosides acting on β4GalT7 as either substrates or inhibitors. In an effort to find efficient substrates and inhibitors of β4GalT7, which would be valuable tools applicable in GAG research, we set out to investigate the active site of β4GalT7 by synthesizing and examining xylosides and xyloside analogs with modifications in the xylose moiety, the endocyclic and exocyclic positions, as well as the aglycon. The overarching aim with these investigations was to pinpoint the requirements of efficient substrates and efficient inhibitors. The synthesized compounds were evaluated in a β4GalT7 assay in combination with molecular docking simulations and conformational analysis by NMR spectroscopy. We found that efficient substrates are formed when keeping the xylose moiety unmodified, but exchanging the endocyclic and/or exocyclic oxygen atoms for sulfur, as well as connecting the xyloside to an aglycon consisting of a fused aromatic system, preferably separated from the xylose part by a short oligoethylene glycol spacer. These structural features can not directly be transferred to a xyloside analog possessing inhibitory activity to gain efficient inhibitors of β4GalT7.}},
author = {{Thorsheim, Karin}},
isbn = {{978-91-7422-535-8}},
keywords = {{Xylosides; β4GalT7; β-1,4-galactosyltransferase 7; glycosaminoglycan; synthesis}},
language = {{eng}},
publisher = {{Lund University, Faculty of Science, Department of Chemistry}},
school = {{Lund University}},
title = {{Exploration of the active site of β4GalT7 – Synthesis of substrates and inhibitors}},
year = {{2017}},
}