Effect of intrinsic and extrinsic factors on the interaction of plant pectin methylesterase and its proteinaceous inhibitor from kiwi fruit.
A proteinaceous pectin methylesterase inhibitor (PMEI) was isolated from kiwi fruit (Actinidia chinensiscv. Hayward) and purified by affinity chromatography on a cyanogen bromide (CNBr) Sepharose 4B-orange PME column. The optimal pH of banana PME activity was 7.0, whereas that for carrot and strawberry PME activity was 9.0. The optimal pH for the binding between kiwi fruit PMEI and these PMEs was 7.0. The kiwi fruit PMEI has a different affinity for PME depending on the plant source. The inhibition kinetics of kiwi fruit PMEI to banana and strawberry PME followed a noncompetitive type, whereas that to carrot PME followed a competitive type. The kiwi fruit PMEI was mixed with banana, carrot, and strawberry PME to obtain PMEI-PME complexes, which were then subjected to thermal (40-80 degrees C, atmospheric pressure) or high-pressure (10 degrees C, 100-600 MPa) treatment. Experimental data showed that the PMEI-PME complexes were easily dissociated by both thermal and high-pressure treatments.
Ly-Nguyen
Binh
B
Laboratory of Food Technology, Department of Food and Microbial Technology, Faculty of Applied Bioscience and Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 22, B-3001 Leuven, Belgium.
Van Loey
Ann M
AM
Smout
Chantal
C
Verlent
Isabel
I
Duvetter
Thomas
T
Hendrickx
Marc E
ME
D002265:Carboxylic Ester Hydrolases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D002846:Chromatography, Affinity; D018552:Daucus carota / Q000201:enzymology; D031985:Fragaria / Q000201:enzymology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010940:Plant Proteins / Q000378:metabolism / Q000494:pharmacology*
C412789:PMEI protein, Actinidia chinensis; D010940:Plant Proteins; D002265:Carboxylic Ester Hydrolases; C022323:pectinesterase