New Zealand Journal of Crop and Horticultural Science abstracts

---

Arginase from kiwifruit: properties and seasonal variation

C. A. HALE¹
C. J. CLARK^2*
H. H. PETACH³
R. M. DANIEL¹

1Department of Biological Science
University of Waikato
Private Bag 3105
Hamilton, New Zealand

2The Horticulture and Food Research
Institute of New Zealand
Palmerston North Research Centre
Private Bag 11 030
Palmerston North, New Zealand

3Department of Chemistry
University of Colorado
Denver, CO 80217-3364
United States

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⁺.

Keywords  Actinidia deliciosa; arginase; arginine; kiwifruit; nitrogen metabolism; seasonal variation

New Zealand Journal of Crop and Horticultural Science, 1997, Vol. 25: 295-301

0114-0671/97/2503-0295 $7.00/0 (c) The Royal Society of New Zealand 1997

Short communication

PDF file of entire paper: medium quality (576K); (scanned from paper original: notes about this process)

---

This year's abstracts | Journal home page | All abstracts | Publishing home page