Enzymic synthesis of indole-3-acetyl-1-O-beta-d-glucose.  I.  Partial purification and characterization of the enzyme from Zea mays.
The first enzyme-catalyzed reaction leading from indole-3-acetic acid (IAA) to the myo-inositol esters of IAA is the synthesis of indole-3-acetyl-1-O-beta-D-glucose from uridine-5'-diphosphoglucose (UDPG) and IAA.  The reaction is catalyzed by the enzyme, UDPG-indol-3-ylacetyl glucosyl transferase (IAA-glucose-synthase).  This work reports methods for the assay of the enzyme and for the extraction and partial purification of the enzyme from kernels of Zea mays sweet corn.  The enzyme has an apparent molecular weight of 46,500 an isoelectric point of 5.5, and its pH optimum lies between 7.3 and 7.6.  The enzyme is stable to storage at zero degrees but loses activity during column chromatographic procedures which can be restored only fractionally by addition of column eluates.  The data suggest either multiple unknown cofactors or conformational changes leading to activity loss.
Leznicki
A J
AJ
Department of Botany and Plant Pathology, Michigan State University, East Lansing 48824-1312, USA.
Bandurski
R S
RS
D002846:Chromatography, Affinity / Q000379:methods; D004951:Esterification; D005964:Glucosyltransferases / Q000302:isolation & purification* / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000378:metabolism*; D011092:Polyethylene Glycols; D014530:Uridine Diphosphate / Q000378:metabolism; D014532:Uridine Diphosphate Glucose / Q000378:metabolism*; D003313:Zea mays / Q000201:enzymology* / Q000378:metabolism
D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; C037009:1-O-indol-3-ylacetylglucose; D011092:Polyethylene Glycols; D014530:Uridine Diphosphate; C030737:indoleacetic acid; D005964:Glucosyltransferases; C071643:indole-3-acetate beta-glucosyltransferase; D014532:Uridine Diphosphate Glucose