| 1. |
- Fromell, Karin, et al.
(författare)
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A particulate platform for bioluminescent immunosensing
- 2007
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 79:22, s. 8601-8607
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Tidskriftsartikel (refereegranskat)abstract
- The present study examines pyruvate kinase-conjugated antibodies for potential use in EUSA applications. The conjugates had an acceptable stability, and the coupling inflicted only minor impairment on the kinase activity. To mimic the setup of an immunoassay under development, a test antigen (BSA) was attached to polystyrene nanoparticles. This arrangement was found to be suitable as solid support for presentation of antigens in sensitive bioluminescence assays. The nanoparticles were well characterized in terms of protein surface load and were used to establish the number of conjugate complexes needed to generate a detectable signal. Under the biochemical conditions employed here, the detection limit of the pyruvate kinase conjugate lies in the femtomole range.
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| 2. |
- Hulting, Greta
(författare)
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Studies of interactions with Streptococcus equi and the host : extracellular proteins of Streptococcus equi subspec. equi and Streptococcus equi subspec. zooepidemicus
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Streptococcus equi subspecies equi (S. equi) causes strangles, a highly contagious and serious disease in the upper respiratory tract of horses, with a worldwide distribution. Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) is regarded as an opportunistic pathogen infecting horses and other animals, and is believed to be the ancestor of S. equi. Pathogenic bacteria have evolved excellent ways of escaping the immune system and other defence mechanisms or have adapted to efficiently colonise specific areas of the host. The overall objective of this thesis was to study the interaction between S. equi and S. zooepidemicus and the host. An important feature for establishment of an infection and survival of the microorganism inside the host is the interaction with, and adherence to, host tissues. In one of the studies, a group of extracellular proteins with sequence similarities with the fibronectin- and collagen-binding protein FNE, were identified and characterised. All of the proteins bound to collagen to different degrees, and one of the proteins, FNEE, was shown to bind both collagen and fibronectin, and mediate a collagen contraction in presence of PDGF-BB. In another study, an additional IgG endopeptidase of S. equi (and S. zooepidemicus), called IdeE2 (IdeZ2) was described. IdeE2 efficiently degrades horse IgG4, and together with another endopeptidase, this enzyme induced protection in a mouse infection model. In a continuation of the IdeE2/IdeZ2 study, on screening a panel of S. zooepidemicus isolates, sequence variation within the ideZ2 gene was discovered, resulting in three major gene variations. However, the variation in this gene did not reflect the origin of the isolates or the MLST group of the strain. Extended computer alignment with IdeS from S. pyogenes, revealed similarities to structures known to be important for endopeptidase activity. The recombinant proteins IdeZ212, IdeZ216 and IdeZ221 all degraded horse IgG highly efficient despite amino acid differences in between the proteins, which argues for the importance of these proteins in the infection process.
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| 3. |
- Hulting, Greta, et al.
(författare)
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Two novel IgG endopeptidases of Streptococcus equi
- 2009
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Ingår i: FEMS Microbiology Letters. - : Oxford University Press (OUP). - 1574-6968 .- 0378-1097. ; 298:1, s. 44-50
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Tidskriftsartikel (refereegranskat)abstract
- Streptococcus equi ssp. equi causes strangles, a highly contagious and serious disease in the upper respiratory tract of horses. Streptococcus equi ssp. zooepidemicus, another subspecies of this genus, is regarded as an opportunistic commensal in horses. The present study describes the characterization of two novel immunoglobulin G (IgG) endopeptidases of these subspecies, IdeE2 and IdeZ2. Both enzymes display sequence similarities with two previously characterized IgG endopeptidases, IdeE of S. equi ssp. equi and IdeZ of S. equi ssp. zooepidemicus. IdeE2 and IdeZ2 display high substrate-specificity in comparison with IdeE and IdeZ, as they both completely cleave horse IgG, while the activity against IgG from mouse, rabbit, cat, cow, sheep and goat is low or absent. The potential use of IdeE and IdeE2 as vaccine components was studied in a mouse infection model. In this vaccination and challenge study, both enzymes induced protection against S. equi ssp. equi infection.
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