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Arginase from kiwifruit: properties and seasonal variation

Abstract
The in vitro activity of arginase (EC 3.5.3.1) was investigated in youngest-mature leaves and roots (1-3 mm diameter) of kiwifruit vines (Actinidia deliciosa var. deliciosa) during an annual growth cycle, and enzyme from root material partially purified. No seasonal trend in the specific activity of arginase was observed in roots. Measurements in leaves, however, rose gradually during early growth and plateaued c. 17 weeks after budbreak. Changes in arginase activity were not correlated with changes in the concentration of arginine (substrate) or glutamine (likely end-product of arginine catabolism) in either tissue during the growth cycle. Purification was by (NH4)2SO4 precipitation and DEAE-cellulose chromatography. The kinetic properties of the enzyme, purified 60-fold over that in crude extracts, indicated a pH optimum of 8.8, and a Km (L-arginine) of 7.85 mM. Partially-purified enzyme was deactivated by dialysis against EDTA, and reactivated in the presence of Mn²⁺, Co²⁺, and Ni²⁺.
Type
Journal Article
Type of thesis
Series
Citation
Hale, C.A., Clark, C.J., Petach, H.H. & Daniel, R.M. (1997). Arginase from kiwifruit: properties and seasonal variation. New Zealand Journal of Crop and Horticultural Science, 25, 295-301.
Date
1997
Publisher
S I R publishing
Degree
Supervisors
Rights
This article has been published in the journal: New Zealand Journal of Crop and Horticultural Science. © 1997 The Royal Society of New Zealand.