Proteome of Rhipicephalus sanguineus tick saliva induced by the secretagogues pilocarpine and dopamine

One dimensional gel electrophoresis was used to separate proteins from the saliva of Rhipicephalus sanguineus female ticks fed on rabbits. Gel slices were subjected to tryptic digestion and analyzed by reversed-phase HPLC followed by MS/MS analysis. The data were compared to a database of salivary proteins of the same tick and to the predicted proteins of the host. Saliva was obtained by either pilocarpine or dopamine stimulation of partially fed ticks. Electrophoretic separations of both yielded products that were identified by mass spectrometry, although the pilocarpine-derived sample was of much better quality. The majority of identified proteins were of rabbit origin, indicating the recycling of the host proteins in the tick saliva, including hemoglobin, albumin, haptoglobin, transferring, and a plasma serpin. The few proteins found that were previously associated with parasitism and blood feeding include 2 glycine-rich, cement-like proteins, 2 lipocalins, and a thyropin protease inhibitor. Among other of the 19 tick proteins identified, albeit with undefined roles, were SPARC and cyclophilin A. This catalog provides a resource that can be mined for secreted molecules that play a role in tick–host interactions.Fundação de Amparo à Pesquisa do Estado de São Paulo-FAPESP 2009/53645-3Fundação de Amparo à Pesquisa do Estado de São Paulo-FAPESP 2007/50869-2Fundação de Amparo à Pesquisa do Estado de São Paulo-FAPESP 2006/54985-4Brazilian National Science Foundation-CNPq 559603/2009-6Brazilian National Science Foundation-CNPq 471946/2010-9Fundação de Amparo à Pesquisa doEstado de Minas Gerais- FAPEMIGIntramural Research Program of the Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Healt