Partial Purification and Properties of a Bacterial Isoamylase

Isoamylase has been prepared by affinity chromatography of a commercial enzyme-preparation from a strain of Cytophaga (also known as a Flavobacterium] or Polyangium). The enzyme was not very stable, but the stability could be improved by calcium ions. The enzyme had a very low but significant activity on pullulan and on alpha-dextrins having maltosyl side-chains. This observation, which is contrary to previous reports, has been related to the specificity of isoamylase and other barterial debranching-enzymes.