Identification of glycogen as the major xylose acceptor in polysomal preparations from chick embryo cartilage cultures

Abstract

UDP-[ 14C]xylose was used to label polysome preparations from chick embryo cartilage cultures derived from limb mesenchymal cells. The highest xylose incorporation was found to be coincident with light polysomes. Chemical and enzymatic characterization of the labeled material suggests that glycogen can serve as a xylose acceptor. Furthermore, glycogen appears to be responsible for virtually all the xylose acceptor activity in these preparations. This glycogen and its associated transferase activity was not associated with polysomes but independently sedimented to a characteristic region of the polysomal gradient. Evidence is discussed which suggests that glycogen synthetase catalyzes the transfer of xylose to glycogen.