Crystal structure of Brugia malayi venom allergen-like protein-1 (BmVAL-1), a vaccine candidate for lymphatic filariasis
- Darwiche, Rabih Division of Biochemistry, Department of Biology, University of Fribourg, Switzerland
- Lugo, Fernanda National School of Tropical Medicine, Baylor College of Medicine, Houston, USA
- Drurey, Claire Wellcome Centre for Molecular Parasitology, University of Glasgow, UK
- Varossieau, Koen Laboratory of Nematology, Wageningen University, The Netherlands
- Smant, Geert Laboratory of Nematology, Wageningen University, The Netherlands
- Wilbers, Ruud H. P. Laboratory of Nematology, Wageningen University, The Netherlands
- Maizels, Rick M. Wellcome Centre for Molecular Parasitology, University of Glasgow, UK
- Schneiter, Roger Division of Biochemistry, Department of Biology, University of Fribourg, Switzerland
- Asojo, Oluwatoyin A. National School of Tropical Medicine, Baylor College of Medicine, Houston, USA
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01.04.2018
Published in:
- International Journal for Parasitology. - 2018, vol. 48, no. 5, p. 371–378
English
Brugia malayi is a causative agent of lymphatic filariasis, a major tropical disease. The infective L3 parasite stage releases immunomodulatory proteins including the venom allergen-like proteins (VALs), which are members of the SCP/TAPS (Sperm-coating protein/Tpx/antigen 5/pathogenesis related-1/Sc7) superfamily. BmVAL-1 is a major target of host immunity with >90% of infected B. malayi microfilaraemic cases being seropositive for antibodies to BmVAL-1. This study is part of ongoing efforts to characterize the structures and functions of important B. malayi proteins. Recombinant BmVAL-1 was produced using a plant expression system, crystallized and the structure was solved by molecular replacement and refined to 2.1 Å, revealing the characteristic alpha/beta/alpha sandwich topology of eukaryotic SCP/TAPS proteins. The protein has more than 45% loop regions and these flexible loops connect the helices and strands, which are longer than predicted based on other parasite SCP/TAPS protein structures. The large central cavity of BmVAL-1 is a prototypical CRISP cavity with two histidines required to bind divalent cations. The caveolin-binding motif (CBM) that mediates sterol binding in SCP/TAPS proteins is large and open in BmVAL-1 and is N-glycosylated. N-glycosylation of the CBM does not affect the ability of BmVAL-1 to bind sterol in vitro. BmVAL-1 complements the in vivo sterol export phenotype of yeast mutants lacking their endogenous SCP/TAPS proteins. The in vitro sterol-binding affinity of BmVAL-1 is comparable with Pry1, a yeast sterol transporting SCP/TAPS protein. Sterol binding of BmVAL-1 is dependent on divalent cations. BmVAL-1 also has a large open palmitate-binding cavity, which binds palmitate comparably to tablysin-15, a lipid-binding SCP/TAPS protein. The central cavity, CBM and palmitate-binding cavity of BmVAL-1 are interconnected within the monomer with channels that can serve as pathways for water molecules, cations and small molecules.
- Faculty
- Faculté des sciences et de médecine
- Department
- Département de Biologie
- Language
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- English
- Classification
- Biological sciences
- License
- License undefined
- Identifiers
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- RERO DOC 309426
- DOI 10.1016/j.ijpara.2017.12.003
- Persistent URL
- https://folia.unifr.ch/unifr/documents/306902
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