Abstract:

A simple method for the extraction of undegraded liver glycogen is described. The molecular weight distribution curve as measured by gradient centrifugation was quite variable and was found to be unrelated to glycogen content. The concentration of malto-oligosaccharides in liver was estimated by a new method and was found to remain constant under conditions in which glycogen content varied considerably. Native glycogen was compared with that prepared in vitro with purified enzymes. Although both preparations were similar in molecular weight and in their appearance under the electron microscope, they differed in the type of breakdown produced by acid, alkali, heat, and ultrasonic vibrations. When glycogen prepared in vitro was submitted to these procedures, its sedimentation coefficient decreased progressively, while native glycogen was broken down preferentially to a lighter population of about S = 100. © 1966.