Isolation and properties of watermelon isocitrate lyase

Jameel, Shahid ; El-Gul, Ted ; Mcfadden, Bruce A. (1984) Isolation and properties of watermelon isocitrate lyase Phytochemistry, 23 (12). pp. 2753-2759. ISSN 0031-9422

Full text not available from this repository.

Official URL:

Related URL:


The glyoxylate cycle enzyme, isocitrate lyase (EC was purified from cotyledons of Citrullus vulgaris (watermelon). The final preparation, which had been 97-fold purified with a specific activity of 16.1 units/mg protein in a yield of 36%, was homogeneous by gel- and immunoelectrophoretic criteria. The tetrameric enzyme had: a molecular weight of 277 000, a sedimentation coefficient of 12.4 s, and a Km for Ds-isocitrate equal to 0.25 mM. Isocitrate lyase from this source is not a glycoprotein as shown by total carbohydrate content after precipitation by trichloroacetic acid of the purified enzyme. Reduction of the enzyme with thiols increased activity and maximal activity was obtained with at least 5 mM dithiothreitol. EDTA partially substituted for thiol in freshly isolated enzyme. Watermelon isocitrate lyase was also protected against thermal denaturation at 60° for at least 1 hr by 5 mM Mg2+ plus 5 mM oxalate. Oxalate was a competitive inhibitor with respect to isocitrate (Ki: 1.5μM, pH7.5,30°).

Item Type:Article
Source:Copyright of this article belongs to Phytochemical Society of Europe.
Keywords:Citrullus vulgaris; Cucurbitaceae; Glyoxylate Cycle; Watermelon Isocitrate Lyase; Seed Germination;
ID Code:13083
Deposited On:11 Nov 2010 04:58
Last Modified:11 Nov 2010 04:58

Repository Staff Only: item control page