Fructose 1,6-bisphosphatase in ripening mango (Mangifera indica L.) fruit.
Kumar R., Selvaraj Y.
Author Affiliation: Fruit Biochemistry Laboratory, Indian Institute of Horticultural Research, Hessaraghatta, Bangalore 560?089, India.
Indian Journal of Experimental Biology 28 : 284-286
Abstract : Mango fruits (of 5 cultivars), harvested at maturity and stored at 25°C and 70% RH, were sampled for fructose 1,6-bisphosphatase extraction and assay at 4 stages of ripening: harvest maturity, 1/2 ripe (pulp colour turning), 3/4 ripe (pulp fully yellow) and table ripe. Enzyme activity was only detected at the 3/4 and table ripe stages, not at harvesting or the 1/2 ripe stage, and increased several fold from the 3/4 ripe stage to the table ripe stage. The enzyme followed Michaelis Menten kinetics and had a Km of 0.028 mM and an optimum pH of 7.5. Enzyme activity was increased by the presence of 0.1 mM citrate and reduced by 0.1, 0.2 and 0.3 mM Zn2+ and 0.3 mM 5? AMP. No activity was detected in the absence of Mg2+.