The enzymic synthesis and degradation of starch. Part XIX. The action of R-enzyme on glycogen

It is shown that R-enzyme, which debranches amylopectin, does not exert a similar hydrolytic action on the glycogen from oysters or from rabbit liver. Evidence is adduced to support the view that this lack of action is due to the higher degree of branching of the glycogen and consequently to the greater compactness of the molecule which makes the majority of the branch links inaccessible to the enzyme. It is worthy of note that the action of R-enzyme provides a simple practical method of distinguishing amylopectins from glycogens.