n. [ Thermo- + Gr. ly`ein to loose + -in. ] (Biochem.) a proteolytic enzyme obtained from the bacterium Bacillus thermoproteolyticus, which hydrolyses the N-terminal amide bonds of hydrophobic amino acid residues in proteins. It is used in studies of protein structure. It has a molecular weight of about 37, 500 and contains zinc and calcium in its active configuration. [ MI11 ] [ PJC ]