| Autor: |
Mondragon-Shem K; Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK., Wongtrakul-Kish K; Ludger Ltd., Culham Science Centre, Oxfordshire, OX14 3EB, UK.; Australian Research Council Centre of Excellence for Nanoscale Biophotonics, Macquarie University, Sydney, Australia., Kozak RP; Ludger Ltd., Culham Science Centre, Oxfordshire, OX14 3EB, UK., Yan S; Department of Chemistry, University of Natural Resources and Life Sciences, 1190, Vienna, Austria.; Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine, A-1210, Vienna, Austria., Wilson IBH; Department of Chemistry, University of Natural Resources and Life Sciences, 1190, Vienna, Austria., Paschinger K; Department of Chemistry, University of Natural Resources and Life Sciences, 1190, Vienna, Austria., Rogers ME; Department of Disease Control, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK., Spencer DIR; Ludger Ltd., Culham Science Centre, Oxfordshire, OX14 3EB, UK., Acosta-Serrano A; Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK. alvaro.acosta-serrano@lstmed.ac.uk. |
| Abstrakt: |
During Leishmania transmission sand flies inoculate parasites and saliva into the skin of vertebrates. Saliva has anti-haemostatic and anti-inflammatory activities that evolved to facilitate bloodfeeding, but also modulate the host's immune responses. Sand fly salivary proteins have been extensively studied, but the nature and biological roles of protein-linked glycans remain overlooked. Here, we characterised the profile of N-glycans from the salivary glycoproteins of Lutzomyia longipalpis, vector of visceral leishmaniasis in the Americas. In silico predictions suggest half of Lu. longipalpis salivary proteins may be N-glycosylated. SDS-PAGE coupled to LC-MS analysis of sand fly saliva, before and after enzymatic deglycosylation, revealed several candidate glycoproteins. To determine the diversity of N-glycan structures in sand fly saliva, enzymatically released sugars were fluorescently tagged and analysed by HPLC, combined with highly sensitive LC-MS/MS, MALDI-TOF-MS, and exoglycosidase treatments. We found that the N-glycan composition of Lu. longipalpis saliva mostly consists of oligomannose sugars, with Man 5 GlcNAc 2 being the most abundant, and a few hybrid-type species. Interestingly, some glycans appear modified with a group of 144 Da, whose identity has yet to be confirmed. Our work presents the first detailed structural analysis of sand fly salivary glycans. |
