Glycogen synthesis in the insect fat body

Abstract

A tissue extract prepared from the fat body of the american cockroach (Periplaneta americana L.) has been shown to contain UDPG-pyrophosphorylase (EC 2.7.7.9) and UDPG-glycogen transglucosylase (EC 2.4.i.ii) activity. The latter enzyme is not stimulated by Glc-6-P. Addition of Glci-P to the system results in a substantial enhancement of [14C]glucose incorporation from UDPG. The present evidence suggests that Glc-i-P is a true activator of UDPG-glycogen transglucosylase of the cockroach fat body.