Sunflower cake is a waste product and an available source of plant proteases for the biotechnological industry of the People's Democratic Republic of Algeria. The purpose of the study is purification, study of the physicochemical properties of protease from Sunflower cake and recommendations for the prospect of using the enzyme in cheese making. Four main aspects were examined, the extraction of the crude enzyme from Sunflower cake, its purification and characterization, the study of the effect of inhibitors on the enzymatic activity and finally the determination of molecular weights and sequencing of amino acids. The purification of the protease produced was carried out by precipitation with ammonium sulphate at 20 and then 65% saturation followed by dialysis against distilled water. Our study allowed us to evaluate the main characteristics of the purified enzymes by gel filtration followed by ion exchange chromatography. Furthermore, the protease showed sensitivity to all the inhibitors studied, also the total inhibitory effect by pepstatin-A classifies the enzyme in the group of aspartate proteases. The amino acid sequence of the purified enzyme gave a MW of 51 kDa. The enzyme in question was coded as NT3 protease. The protease showed sensitivity of the enzyme to a cysteine protease inhibitor (iodoacetamide), metalloprotease inhibitor (EDTA) and metal inhibitors (Ca, Fe, Zn, Cu, and Mg). This sensitivity was most pronounced towards pepstatin-A, which succeeded in suppressing almost all of the clotting activity of the enzyme thus pronouncing the presence of an Aspartyl protease in our clotting agent. The molecular weight of the amino acid sequence of the NT3 protease was 3 kDa different from that obtained by gel filtration (48 kDa). The scientific article discusses the prospects for using Sunflower cake protease

doi.org/10.32737/0005-2531-2024-29-43