Factors affecting the binding between fusicoccin and plasma membranes from maize roots

Plasma membranes have been purified from roots of maize (Zea mays L.) using a two-phase aqueous polymer system, dextran-polyethylene glycol. The plant material was homogenized in the presence of a mixture of natural protease inhibitors from potato (Solanum tuberosum L.); these inhibitors have been s...

Full description

Saved in:
Bibliographic Details
Published in:Planta 1993-03, Vol.189 (3), p.301-305
Main Authors: Abramycheva, N.Y. (Institute of Agricultural Biotechnology, Moscow (Russian Federation)), Nesterenko, M.V, Babakov, A.V
Format: Article
Language:English
Subjects:
ADSORCION
ADSORPTION
Binding sites
CELL MEMBRANES
Corn
Fusicoccin
Gels
Homogenization
Kinetics
Lipids
MEMBRANAS CELULARES
MEMBRANE CELLULAIRE
PLANT GROWTH SUBSTANCES
Plant roots
Plants
Plasmamembran
Protease inhibitors
RACINE
RAICES
ROOTS
SUBSTANCE DE CROISSANCE VEGETALE
SUSTANCIAS DE CRECIMIENTO VEGETAL
Wurzel
Zea
ZEA MAYS
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Plasma membranes have been purified from roots of maize (Zea mays L.) using a two-phase aqueous polymer system, dextran-polyethylene glycol. The plant material was homogenized in the presence of a mixture of natural protease inhibitors from potato (Solanum tuberosum L.); these inhibitors have been shown to be more effective than phenylmethylsulfonyl fluoride in suppressing the endogenous proteases in maize roots. Inhibition of proteolysis in the homogenization medium markedly increased (about tenfold) the number of low-affinity binding sites for fusicoccin (FC). In addition, storage of plasma membranes at -20° C decreased both the number of the low-affinity sites and their dissociation constant (KD); this effect was in all probability caused by lipid peroxidation. The presence of EDTA throughout isolation and storage of the plasma membranes stabilized the parameters of FC binding to the membranes. The kinetics of binding of [3H]dihydroFC and the competition between [3H]dihydroFC and FCs A, C, J, and H were determined for the low-affinity sites. It was found that (i) the rate constant of association between FC and the low-affinity binding sites is about two orders of magnitude lower than that for the high-affinity sites; (ii) different FCs can be arranged in the order of decreasing avidity for the low-affinity FC-binding site: FC A > FC C > FC J > FC H.
ISSN:0032-0935
1432-2048
DOI:10.1007/BF00194425