Procedure After completing the mutagensis of the branching enzyme, we sequenced the entire gene to check the new sequence. Once the proper sequence was determined to be the present, we performed a series of expression, purification, assay, and crystallization experiments. The activity of the branching enzyme was measured by the Phosphorylase A assay. In this reaction, the branching enzyme and the Phosphorylase act together to build the glycogen molecule including 14C-glucose. Activity of the enzyme can then be determined by the amount of radiation included in the molecule. The pure enzyme is still in the process of trying to be crystallized. If enzyme crystals are obtained, a three-dimensional structure of the enzyme can be deduced.