The first serine protease inhibitor from Lasiodora sp. (Araneae: Theraphosidae) hemocytes

► An extract from Lasiodora sp. hemocytes inhibited different serine proteases. ► Hemocyte extract inhibited growth of Bacillus subtilis and Enterococcus faecalis. ► An elastase inhibitor (EILaH) with 8274 Da was purified from hemocytes. ► EILaH (Ki: 0.32 nM) amino terminal sequence is LPC(PF)PYQQELTC. ► EILaH showed bacteriostatic activity against E. faecalis.