XXXX trypsin inhibitors present in the tick larvae: isolation, characterization, and partial primary structure determination.

@entity235 @entity535 @entity563 @entity3367 @entity278 @entity214
Blood sucking animals are a rich source of proteinase inhibitors mainly those that interfere in their host hemostatic systems. The tick @entity278 is an ectoparasite of @entity235 and other animals. The aims of this work were the purification and characterization of @entity563 proteinase inhibitors present in @entity278 larvae (RsTI). The inhibitors (RsTI) were isolated by affinity chromatography on trypsin- @entity3367 and ion exchange chromatographies in Resource Q and Mono S columns. These RsTIs were separated in around 12 different protein peaks, when they showed molecular masses between 8 and 18 kDa, by @entity214 -PAGE. Purified RsTIs presented differences in the specificity for different @entity563 proteinases. RsTIQ2 was, better inhibitor than RsTIQ7 and RsTIS5 for neutrophil elastase, plasmin, and HuPK with dissociation constants (K(i)) of 1.3, 3.2, and 22 nM, respectively. Other inhibitors such as RsTIQ7, RsTIS3, and RsTIS5 also affected neutrophil elastase and plasmin with K(i) in the nM range. The RsTIQ2, RsTIQ7, and RsTIS5 @entity535 sequence data allowed classifying them as members of the Kunitz-type @entity563 proteinase inhibitor family, even though the RsTI role is still unknown. Our present results showed that @entity563 proteinase inhibitors from @entity278 are similar to inhibitors from Boophilus microplus other hard tick species, suggesting a similar role of these inhibitors in hard tick species and also as a potential tool to generate or improve vaccine against different ectoparasites with an unique antigen.
