2026-04-13T06:39:12Zhttps://recercat.cat/oai/requestoai:recercat.cat:2445/2259482026-04-07T22:22:04Zcom_2072_1057col_2072_478781col_2072_478917
RECERCAT
author
Feldwisch, Joachim
author
Vente, Andreas
author
Zettl, Rolf
author
Bako, Laszlo
author
Campos Martínez, Narciso
author
Palme, Klaus
2026-01-22T11:48:01Z2026-01-22T11:48:01Z1994-08-152026-01-22T11:48:01Z
We isolated membrane vesicles from maize (Zea mays L.) coleoptiles and identified in these vesicles a 58 kDa (pm58) and a 60 kDa (pm60) protein by photoaffinity labelling with 5-azido-[7-3H]indole-3-acetic acid ([3H]N3IAA). Photoaffinity labelling was effectively competed for by auxins as well as by flavonoids. The labelled proteins were solubilized by Triton X-114 from the vesicles and partially purified. Microsequence analysis revealed that pm60 is a beta-glucosidase. This was confirmed by biochemical and immunological analysis. We show that pm60 has a beta-D-glucoside glucohydrolase (EC 3.2.1.21) activity. It uses p-nitro-phenyl beta-D-glucopyranoside (PNPG) as a substrate, with a pH optimum of 5.0. The Km for PNPG is 0.652 mM and the Vmax. 6.24 mumol.min-1.mg-1. The beta-glucosidase activity of pm60 was competitively inhibited by IAA and 1-naphthylacetic acid as well as by gluconolactam and glucose. N-terminal amino-acid-sequence analysis of pm58 revealed similarity to pm60, suggesting that both proteins are encoded by different members of a gene family.
(c) Feldwisch, J. et al., 1994 info:eu-repo/semantics/openAccess
Glucòsids
Biologia molecular vegetal
Glucosides
Plant molecular biology
Characterization of two membrane-associated β-glucosidases from maize coleoptiles
info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion