Amblyomma americanum serpin 41 (AAS41) inhibits inflammation by targeting chymase and chymotrypsin.

ABSTRACT: Ticks inject serine protease inhibitors (serpins) into their feeding sites to evade serine protease-mediated host defenses against tick-feeding. This study describes two highly identitical (97%) but functionally different Amblyomma americanum tick saliva serpins (AAS41 and 46) that are secreted at the inception of tick-feeding. We show that AAS41, which encodes a leucine at the P1 site inhibits inflammation system proteases: chymase (SI = 3.23, Ka = 5.6 ± 3.7X10³M^-1 s^-1) and α-chymotrypsin (SI = 3.18, Ka = 1.6 ± 4.1X10⁴M^-1 s^-1), while AAS46, which encodes threonine has no inhibitory activity. Similary, rAAS41 inhibits rMCP-1 purified from rat peritonuem derived mast cells. Consistently, rAAS41 inhibits chymase-mediated infla

SUBMITTER: Kim TK 

PROVIDER: S-EPMC11005088 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature