Enzymatic characterization of the spine extract. Kinetic data of velocity over concentration of substrate, after the incubation of spine aqueous extract (12 μg) with (A) Z-R-MCA and (B) Abz-GIVRAK(Dnp)-OH. (C) Enzyme titration using E-64 inhibitor, performed over Abz-GIVRAK(Dnp)-OH substrate. (D) Determination of pH for optimum activity of spine aqueous extract, over Abz-GIVRAK(Dnp)-OH substrate. (E) HPLC profile, in λ = 365 nm, of the products of complete hydrolysis of the Abz-GIVRAK(Dnp)-OH substrate by spine aqueous extract. (F) Mass spectrometry analysis of the products of Abz-GIVRAK(Dnp)-OH hydrolysis by spine aqueous extract.