The crystal structures of two salivary cystatins from the tick Ixodes scapularis and the effect of these inhibitors on the establishment of Borrelia burgdorferi infection in a murine model

0345737 - BC 2011 RIV GB eng J - Journal Article
Kotsyfakis, Michalis - Horká, Helena - Salát, Jiří - Andersen, J. F.
The crystal structures of two salivary cystatins from the tick Ixodes scapularis and the effect of these inhibitors on the establishment of Borrelia burgdorferi infection in a murine model.
Molecular Microbiology. Roč. 77, č. 2 (2010), s. 456-470. ISSN 0950-382X. E-ISSN 1365-2958
R&D Projects: GA AV ČR KJB500960702; GA AV ČR IAA600960811
Institutional research plan: CEZ:AV0Z60220518
Keywords : INVARIANT CHAIN FRAGMENT * EGG-WHITE CYSTATIN * CATHEPSIN-L * CYSTEINE PROTEINASES * SIALOSTATIN-L * ENDOPEPTIDASE
Subject RIV: EC - Immunology
Impact factor: 4.819, year: 2010

We have previously demonstrated that two salivary cysteine protease inhibitors from the Borrelia burgdorferi (Lyme disease) vector Ixodes scapularis play an important role in tick biology. Here we show that sialostatin L2 - but not sialostatin L - facilitates the growth of B. burgdorferi in murine skin. To examine the structural basis underlying these differential effects of the two sialostatins, we have determined the crystal structures of both sialostatin L and L2. This is the first structural analysis of cystatins from an invertebrate source. Sialostatin L2 crystallizes as a monomer with an 'unusual' conformation of the N-terminus, while sialostatin L crystallizes as a domain-swapped dimer with an N-terminal conformation similar to other cystatins. Deletion of the 'unusual' N-terminal five residues of sialostatin L2 results in marked changes in its selectivity, suggesting that this region is a particularly important determinant of the biochemical activity of sialostatin L2.
Permanent Link: http://hdl.handle.net/11104/0186940