The myrosinase-glucosinolate interaction mechanism studied using some synthetic competitive inhibitors.
Using synthetic deoxy-glucotropaeolins (6d-GTL, 4d- GTL, 3d-GTL, 2d-GTL) as substrates, myrosinase activity was studied in comparison to that determined on native glucotropaeolin (GTL) isolated from ripe Lepidium sativum seeds. When the deoxy substrates were used, in addition to an overall strong reaction rate decline, a significant decrease in the reaction rate was observed in going from 6d- to 2d-GTL. This finding allows us to propose a mechanism of catalysis which appears to be similar in many respects to that established for beta-glucosidases. Finally, 2d-GTL was shown to be the first strong competitive inhibitor of myrosinase ever reported.
Iori
R
R
Istituto Sperimentale per le Colture Industriali, Bologna, Italy.
Rollin
P
P
Streicher
H
H
Thiem
J
J
Palmieri
S
S
D001665:Binding Sites; D001667:Binding, Competitive; D004791:Enzyme Inhibitors; D005961:Glucosinolates / Q000737:chemistry* / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D006877:Hydroxamic Acids / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D017879:Isothiocyanates; D007700:Kinetics; D008956:Models, Chemical; D011487:Protein Conformation; D012639:Seeds; D013379:Substrate Specificity; D013863:Thioglucosides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism
D004791:Enzyme Inhibitors; D005961:Glucosinolates; D006877:Hydroxamic Acids; D017879:Isothiocyanates; D013863:Thioglucosides; C060321:glucotropeolin; D006026:Glycoside Hydrolases; C022739:thioglucosidase