Sökning: onr:"swepub:oai:DiVA.org:uu-192025" >
Single amino acid e...
Single amino acid exchange in bacteriophage HK620 tailspike protein results in thousand-fold increase of its oligosaccharide affinity
-
Broeker, N. K. (författare)
-
Gohlke, U. (författare)
-
Müller, J. J. (författare)
-
visa fler...
-
- Uetrecht, Charlotte (författare)
- Uppsala universitet,Molekylär biofysik
-
Heinemann, U. (författare)
-
Seckler, R. (författare)
-
Barbirz, S. (författare)
-
visa färre...
-
(creator_code:org_t)
- 2012-08-24
- 2013
- Engelska.
-
Ingår i: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 23:1, s. 59-68
- Relaterad länk:
-
https://academic.oup...
-
visa fler...
-
https://urn.kb.se/re...
-
https://doi.org/10.1...
-
visa färre...
Abstract
Ämnesord
Stäng
- Bacteriophage HK620 recognizes and cleaves the O-antigen polysaccharide of Escherichia coli serogroup O18A1 with its tailspike protein (TSP). HK620TSP binds hexasaccharide fragments with low affinity, but single amino acid exchanges generated a set of high-affinity mutants with submicromolar dissociation constants. Isothermal titration calorimetry showed that only small amounts of heat were released upon complex formation via a large number of direct and solvent-mediated hydrogen bonds between carbohydrate and protein. At room temperature, association was both enthalpy- and entropy-driven emphasizing major solvent rearrangements upon complex formation. Crystal structure analysis showed identical protein and sugar conformers in the TSP complexes regardless of their hexasaccharide affinity. Only in one case, a TSP mutant bound a different hexasaccharide conformer. The extended sugar binding site could be dissected in two regions: first, a hydrophobic pocket at the reducing end with minor affinity contributions. Access to this site could be blocked by a single aspartate to asparagine exchange without major loss in hexasaccharide affinity. Second, a region where the specific exchange of glutamate for glutamine created a site for an additional water molecule. Side-chain rearrangements upon sugar binding led to desolvation and additional hydrogen bonding which define this region of the binding site as the high-affinity scaffold.
Nyckelord
- bacterial O-antigen
- carbohydrate interaction
- site-directed mutagenesis
- structural thermodynamics
- tailspike protein
- bacteriophage hk620 tailspike protein
- carbohydrate
- glutamic acid
- glutamine
- mutant protein
- O antigen
- oligosaccharide
- solvent
- unclassified drug
- virus protein
- amino acid substitution
- article
- bacteriophage
- bacteriophage hk620
- binding site
- complex formation
- crystal structure
- dissociation constant
- enthalpy
- Escherichia coli
- heat
- hydrogen bond
- hydrophobicity
- isothermal titration calorimetry
- nonhuman
- priority journal
- protein binding
- reaction analysis
- room temperature
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
Hitta via bibliotek
Till lärosätets databas