Loss of second and sixth conserved cysteine residues from trypsin inhibitor-like cysteine-rich domain-type protease inhibitors in Bombyx mori may induce activity against microbial proteases
The Cys2nd and Cys6th were missing from silkworm TIL-type protease inhibitors. Introduction of Cys2nd and Cys6th may cause incorrect disulfide bond formation. Cysteine mutations caused a slight change in the secondary structure composition. Cysteine mutations affected the multimerization states of protease inhibitors. Cys2nd and Cys6th mutations dramaticly reduced the activity of protease inhibitors.