Hexose kinases of avocado

The subcellular location and properties of enzymes concerned with the phosphorylation of glucose and fructose in avocado (Persea americana Mill. cv. Hass) have been studied. A substantial amount of glucose‐phosphorylating activity was particulate and fractionation of extracts by sucrose density gradient centrifugation indicated that most of this activity was associated with the mitochondria. Three hexose‐phosphorylating enzymes were resolved by DEAE‐cellulose chromatography of the cytosolic fraction. These were a hexokinase (EC 2.7.1.1), which had strong preference for glucose as substrate, and two specific fructokinases (EC 2.7.1.4). ATP was the preferred phosphoryl donor for the hexose kinases of avocado.