Changes in ATP related compounds and IMP-degrading enzyme activity of New Zealand golden snapper [Pagrus auratus]

Abstract

The amounts of ATP related compounds during storage and some properties of IMP degrading enzyme in the ordinary muscle of the golden snapper Pagrus auratus from waters around New Zealand were examined. When the muscle were stored for five days at 4°C, IMP remarkably decreased and hypoxanthine increased, whereas the amount of inosine was low and scarcely changed during storage. The amounts of IMP in the muscle hardly changed during storage for 43days at-20°C. IMP was degraded optimally at pH6.2 and pH8.4 in dorsal muscle homogenate of golden snapper. The IMP-degrading activity in the minced dorsal muscle decreased by the storage for one day at 4°C, showing 82.5% of initial activity, and since then, the activity decreased rapidly, showing 17.5% after seven days of storage. The IMP-degrading activity of crude enzyme extracted from the golden snapper muscle using the detergent remarkably increased at pH8.0 in the presence of 2mM Mg2+ and stabilized at pH7.0 for 48h (2±1°C).