Figure 2From: Cathepsin B/X is secreted by Echinometra lucunter sea urchin spines, a structure rich in granular cells and toxinsEnzymatic 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.Back to article page