| Prickly ash (Zanthoxylum bungeanum Maxim) seed protein was hydrolyzed with pepsin and acid protease respectively. With inhibitory rate as indicator, the crude enzyme solutions (peptide A and peptide B) were in turn molecular retained, isolated and purified by ultrafiltration and Sephadex G-50 gel chromatography. The relative molecular weights of the main antimicrobial peptides were measured by Tricine-SDS-PAGE. The results showed that after the crude enzyme solutions of two hydrolysates were ultrafiltrated, the components with the relative molecular weights in the range of 5-10 kD (peptide A-b and peptide B-b) had the highest antibacterial activity on E.coli
, reaching 62.79% and 66.94%. Four components were isolated from peptide A-b and peptide B-b by gel chromatography. Components G4 (peptide A-b-Ⅳ) from peptide A-b had the highest antibacterial activity, and the inhibitory rate on E.coli was 100%. Components F3 (peptide B-b-Ⅲ) from peptide B-b had the highest antibacterial activity, and the inhibitory rate on E.coli was 69.99%.The relative molecular weights of peptide A-b-Ⅳ and peptide B-b-Ⅲ were 8.11 kD and 10.80 kD, respectively. |
