title: Podophyllum peltatum possesses a beta-glucosidase with high substrate specificity for the aryltetralin lignan podophyllotoxin.
abstract: A beta-glucosidase with high specificity for podophyllotoxin-4-O-beta-D-glucopyranoside was purified from the leaves of Podophyllum peltatum. The 65-kDa polypeptide had optimum activity at pH 5.0 and was essentially inactive at pH 6.5 or above. Maximum catalytic activity of this glucosidase was obtained at 45 degrees C, but the enzyme was not heat stable. This beta-glucosidase displayed higher substrate specificity for podophyllotoxin-4-O-beta-D-glucopyranoside than for the other lignans tested, and for the (1-->3) linkage of laminaribiose than for other glucosidic linkages.
authors.affiliation: Natural Products Utilization Research Unit, Agricultural Research Service, United States Department of Agriculture, P.O. Box 8048, University, MS 38677, USA. fdayan@ars.usda.gov
authors.forename: Franck E
authors.initials: FE
authors.lastname: Dayan
authors.forename: Jeanne M
authors.initials: JM
authors.lastname: Kuhajek
authors.forename: Camilo
authors.initials: C
authors.lastname: Canel
authors.forename: Susan B
authors.initials: SB
authors.lastname: Watson
authors.forename: Rita M
authors.initials: RM
authors.lastname: Moraes
mesh_terms: D004187:Disaccharides / Q000737:chemistry / Q000378:metabolism; D004795:Enzyme Stability; D005960:Glucosides / Q000737:chemistry / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D018515:Plant Leaves / Q000201:enzymology; D011034:Podophyllotoxin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism*; D028144:Podophyllum peltatum / Q000201:enzymology*; D013379:Substrate Specificity; D013696:Temperature; D001617:beta-Glucosidase / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D004187:Disaccharides; D005960:Glucosides; C430086:podophyllotoxin 4-O-glucopyranoside; C014637:laminaribiose; D001617:beta-Glucosidase; D011034:Podophyllotoxin