This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (39) Citing Articles via Google Scholar Google Scholar Articles by Copeland, L. Articles by Turner, J. F. Search for Related Content PubMed PubMed Citation Articles by Copeland, L. Articles by Turner, J. F. Agricola Articles by Copeland, L. Articles by Turner, J. F.

Articles

Fructokinase (Fraction III) of Pea Seeds ¹

Department of Agricultural Chemistry, University of Sydney, N.S.W. 2006, Australia

A second fructokinase (EC 2.7.1.4) was obtained from pea seed (Pisum sativum L. var. Progress No. 9) extracts. The enzyme, termed fructokinase (fraction III), was specific for fructose and had little activity with glucose. With fructose concentrations above 0.25 millimolar, there was strong substrate inhibition at the optimum pH (8.0) and also at pH 6.6. The apparent K_m values at pH 8.0 for fructose and glucose were 0.06 millimolar and 0.14 millimolar, respectively. The apparent K_m for Mg adenosine 5'-triphosphate (MgATP) was 0.06 millimolar and excess MgATP was inhibitory. Mg²⁺ was essential for activity but the enzyme was inhibited by excess Mg²⁺ or ATP. Mg adenosine 5'-pyrophosphate was also inhibitory. Activity was stimulated by the addition of monovalent cations: of those tested K⁺, Rb⁺, and NH₄⁺ were the most effective. The possible role of fructokinase (fraction III) is discussed.

This article has been cited by other articles:

				L. KARNI and B. ALONI Fructokinase and Hexokinase from Pollen Grains of Bell Pepper (Capsicum annuum L.): Possible Role in Pollen Germination under Conditions of High Temperature and CO2 Enrichment Ann. Bot., November 1, 2002; 90(5): 607 - 612. [Abstract] [Full Text] [PDF]

				S. Odanaka, A. B. Bennett, and Y. Kanayama Distinct Physiological Roles of Fructokinase Isozymes Revealed by Gene-Specific Suppression of Frk1 and Frk2 Expression in Tomato Plant Physiology, July 1, 2002; 129(3): 1119 - 1126. [Abstract] [Full Text] [PDF]

				T. C. Fox, B. J. Green, R. A. Kennedy, and M. E. Rumpho Changes in Hexokinase Activity in Echinochloa phyllopogon and Echinochloa crus-pavonis in Response to Abiotic Stress Plant Physiology, December 1, 1998; 118(4): 1403 - 1409. [Abstract] [Full Text]