| 1. |
- Gjelstrup, Louise Carstensen, et al.
(författare)
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The role of higher-order protein structure in supporting binding by heteroclitic monoclonal antibodies: The monoclonal antibody KIM185 to CD18 also binds C4-binding protein
- 2011
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Ingår i: Molecular Immunology. - : Elsevier BV. - 1872-9142 .- 0161-5890. ; 49:1-2, s. 38-47
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Tidskriftsartikel (refereegranskat)abstract
- Heteroclitic monoclonal antibodies are characterized by the ability to bind multiple epitopes with little or no similarity. Such antibodies have been reported earlier, but insight into to the molecular basis of this propensity is limited. Here we report that the KIM185 antibody to human CD18 reacts with the plasma protein C4b-binding protein (C4BP). This was revealed during affinity purification procedures where human serum was incubated with surfaces coated with monoclonal antibodies to CD18. Other monoclonal antibodies to CD18 (KIM127 and TS1/18) showed no such interaction with C4BP. We constructed a sandwich-type time-resolved immunofluorometric assay using KIM185 both as capture and developing antibody. By use of proteolytic fragments of KIM185 and recombinant deletion mutants of C4BP the interaction sites were mapped to the variable region of KIM185 and the oligomerization domain of C4BP, respectively. C4BP is a large oligomeric plasma protein that binds activated complement factor C4b and other endogenous ligands as well as microorganisms. By use of the recent crystallographic data on the structure of CD11c/CD18 and prediction of the secondary structure of the C4BP oligomerization domain, we show that epitopes bound by KIM185 in these proteins are unlikely to share any major structural similarity. However, both antigens may form oligomers that would enable avid binding by the antibody. Our report points to the astonishing ability of heteroclitic antibodies to accommodate the binding of multiple proteins with no or little structural similarity within the confined space of the variable regions. (C) 2011 Elsevier Ltd. All rights reserved.
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| 2. |
- Henic, Emir, et al.
(författare)
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Mannan-binding lectin in women with a history of recurrent vulvovaginal candidiasis.
- 2010
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Ingår i: European Journal of Obstetrics, Gynecology, and Reproductive Biology. - : Elsevier BV. - 0301-2115. ; 148:2, s. 163-165
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To determine the serum concentration of mannan-binding lectin (MBL), a component of the innate immune system, in women with a history of recurrent vulvovaginal candidiasis (RVVC) and to correlate the result to candida-cultures, contraceptive use, if any, and to different antifungal therapies. STUDY DESIGN: Twenty-nine women with a history of RVVC were investigated. Cultures of vulvar and vaginal samples were grown on chromogenic agar. Serum levels of MBL were determined by a sandwich time-resolved immunofluorometric assay, using anti-MBL coated microtiter wells containing samples, which were washed, incubated with biotinylated anti-MBL followed by europium-labeled streptavidin and measured by time-resolved flourometry. RESULTS: The median MBL level was higher in the RVVC cases than in 30 women with no history of genital candida infection who served as a comparison group (p=0.006). It was also higher in the candida-positive than in the culture-negative RVVC (p=0.02). The median concentration of MBL was also higher in hormonal contraceptive users as compared to condom-users and those using no contraceptive at all (p=0.03). CONCLUSION: The result indicates a role of MBL in RVVC and the production may correlate to vulvar/vaginal colonization by Candida, hormonal contraceptive use, and antifungal therapies.
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| 3. |
- Thiel, Volker, et al.
(författare)
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Occurrence and fate of fatty acyl biomarkers in an ancient whale bone (Oligocene, El Cien Formation, Mexico)
- 2014
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Ingår i: Organic Geochemistry. - : Elsevier BV. - 0146-6380 .- 1873-5290. ; 68:Mar, s. 71-81
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Tidskriftsartikel (refereegranskat)abstract
- The taphonomic and diagenetic processes by which organic substances are preserved in animal remains are not completely known and the originality of putative metazoan biomolecules in fossil samples is a matter of scientific discussion. Here we report on biomarker information preserved in a fossil whale bone from an Oligocene phosphatic limestone (El Cien Fm., Mexico), with a focus on fatty acyl compounds. Extracts were quantitatively analysed using gas chromatography-mass spectrometry (GC-MS) and, to identify macromolecular-linked remains, demineralised extraction residues were subjected to catalytic hydropyrolysis (HyPy). To better recognise potential authentic (i.e. animal-derived) lipids, the data from the ancient bone were compared with those obtained from (i) the adjacent host sediment of the fossil and (ii) a recent whale (Phocoena phocoena) vertebra. In addition, the spatial distribution of organic and inorganic species was observed at the μm level by imaging MS (time-of-flight-secondary ion mass spectrometry, ToF-SIMS). Our results revealed a rather even distribution of hydrocarbon-, O- and N-containing ions in the trabecular network of the ancient bone. A different, more patchy arrangement of organic compounds was evident in the former marrow cavities that were partly cemented by clotted micrites of putative microbial origin. The concentration of fatty acids (FAs) in the ancient bone was in the permil range of the amount extracted from the recent whale vertebra. Endogenous compounds, including monoenoic n-C16and n-C18 as well as branched FAs, were identified in the fossil bone by comparison with the host sediment. Ca. 80% of the prevalent n-C16 and n-C18 moieties in the ancient bone were extractable as FAs, whereas ca. 20% were covalently bound in the non-saponifiable kerogen fraction. Ample pyrite precipitates, distinctive 10-methyl branched FAs and microbial microborings ("tunneling") indicate that sulfate reducers and collagen-degrading actinomycetes were central players in the microbial decomposition of the bone. Similarities with reported microbial FA patterns suggest that the FAs in the fossil bone were largely contributed by these microbial "last eaters". The results highlight some of the degradation and preservation mechanisms during marine FA diagenesis in the "natural laboratory" of bones, and therefore the processes that lead to either degradation, preservation, or introduction of these widespread biomolecules in the fossils of ancientmarine animals.
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