On the role of hydroxyl-containing amino acids in trypsin inhibitors

Abstract

1. 1. The exposure to solvent of the lima bean trypsin inhibitor tyrosine has been examined by spectrophotometric titration, as well as chemical reactivity with cyanuric fluoride and N-acetylimidazole; this residue has been found to be highly inaccessible. 2. 2. Acetylation experiments have indicated that modification of residues susceptible to reaction with N-acetylimidazole interferes with the trypsin inhibitory activity of ovomucoid and soybean trypsin inhibitor. 3. 3. Circular dichroism studies have shown the structural stability of all three inhibitors, since the spectra are little affected even at high levels of acetylation.