Alignment of deduced amino acid sequence of P. megistus serpin (PMSRP1) compared with different insect serpins. Identical amino acid residues between PMSRP1 and other serpins are shaded grey. The conserved reactive centre loop is boxed, the hinge regions and the PF residues of the “shutter region” are underlined. The putative proteolytic cleavage site, predicted by the alignment, is indicated by P1/P1′. Predicted serine proteases cleavage sites are marked in bold typeface. The true P1-P1′ of PMSRP1 (putative P4′-P5′) scissile bond is indicated by an arrow. The secondary structure was predicted by using the Jnet prediction method (http://www.compbio.dundee.ac.uk/~www-jpred/submit.html), ß-strands are highlighted in green, α-helices in red and the extended region in blue. The GenBank accession numbers for the analysed sequences are: Culex quinquefasciatus (XP 001865071), Aedes aegypti (XP 001658641), Anopheles gambiae (XP 314158), Ctenocephalides felis (AAN73325), Lutzomyia longipalpis (ABV60345), Bombus impatiens (XP 003487908), Bombus terrestris (XP 003399187), Nasonia vitripennis (XP 001606111), Drosophila melanogaster (CAB 63097). Acyrthosiphon pisum (BAH 71022), Tribolium castaneum (EFA 09186) and Bombyx mori (NP 001037021).