| 1. |
- Egge-Jacobsen, Wolfgang, et al.
(författare)
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O-Linked glycosylation of the PilA pilin protein of francisella tularensis : identification of the endogenous protein-targeting oligosaccharyltransferase and characterization of the native oligosaccharide
- 2011
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Ingår i: Journal of Bacteriology. - Baltimore : Williams & Wilkins. - 0021-9193 .- 1098-5530. ; 193:19, s. 5487-5497
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Tidskriftsartikel (refereegranskat)abstract
- Findings from a number of studies suggest that the PilA pilin proteins may play an important role in the pathogenesis of disease caused by species within the genus Francisella. As such, a thorough understanding of PilA structure and chemistry is warranted. Here, we definitively identified the PglA protein-targeting oligosaccharyltransferase by virtue of its necessity for PilA glycosylation in Francisella tularensis and its sufficiency for PilA glycosylation in Escherichia coli. In addition, we used mass spectrometry to examine PilA affinity purified from Francisella tularensis subsp. tularensis and F. tularensis subsp. holarctica and demonstrated that the protein undergoes multisite, O-linked glycosylation with a pentasaccharide of the structure HexNac-HexHex-HexNac-HexNac. Further analyses revealed microheterogeneity related to forms of the pentasaccharide carrying unusual moieties linked to the distal sugar via a phosphate bridge. Type A and type B strains of Francisella subspecies thus express an O-linked protein glycosylation system utilizing core biosynthetic and assembly pathways conserved in other members of the proteobacteria. As PglA appears to be highly conserved in Francisella species, O-linked protein glycosylation may be a feature common to members of this genus.
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| 2. |
- Rajan, Akhil, et al.
(författare)
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Epitaxial lift-off of II-VI semiconductors from III-V substrates using a MgS release layer
- 2013
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 114:24, s. 243510-
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Tidskriftsartikel (refereegranskat)abstract
- Epitaxial lift-off (ELO) is a post-growth process that allows an epitaxial layer to be removed from its original substrate and transferred to a new one. ELO has previously been successfully demonstrated for III-V materials and also ZnSe based II-VI semiconductors using a MgS sacrificial layer. Following the recent successful growth of epitaxial MgS layers on GaP and InP substrates, in this paper we compare ELO of II-VI epilayers grown on GaP, GaAs, and InP substrates using MgS sacrificial layers in the range of 7-15 nm thick. Good quality lifted layers are obtained rapidly from InP and GaAs substrates. For GaP substrates, ELO is much slower and good quality lifts have only been achieved with ZnSe epilayers. Photoluminescence spectra obtained from epitaxial layers before and after ELO show changes in peak positions, which are compatible with changes of strain in the layer. The layers produced by ELO are flat and free of cracks, suggesting that this is an efficient and convenient method for the transfer of II-VI epitaxial layers to other substrates.
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