Identification of tick PM proteins.
(A) Western blot analysis of PM proteins from the tick gut. Gut samples dissected from unfed and fed ticks were immunoblotted using antibodies generated against the PM. Specificity of anti-PM antisera was tested against normal mouse serum (present in fed ticks) or by replacing the primary antibody with normal mouse serum. Arrows denote proteins (between 46-175 kDa) that are preferentially recognized by the anti-PM antibodies, suggesting specific association with the PM in the fed vector gut. (B) Identification of abundant PM proteins. PM samples were isolated from fed ticks and extensively rinsed with water. Proteins in the solubilized PM fraction were separated by SDS-PAGE and stained with Coomassie Brilliant Blue. Clearly resolved and detectable protein bands, as indicated by arrows (1-3), were excised and analyzed by LC-MS/MS spectrometry for identification of the proteins. Migration of the protein MW marker is indicated on the left (in kDa). Asterisks indicate the IsCDA protein that is the focus of the present work.