Trypsin-chymotrypsin inhibitors from the tick, Boophilus microplus

The eggs of the cattle tick, Boophilus microplus, contain at least two proteolytic enzyme inhibitors which have been purified and partially characterized. One of these is closely related to an inhibitor from larval ticks previously purified. It is similar in general properties, in amino acid composition and it cross-reacts immunologically with the larval protein. The egg and larval proteins are, however, largely or completely stage-specific. The significance of this to the study of the host-parasite interaction is discussed.