Abstract
Recent experimental results that we have obtained on potato phosphorylase [EC 2.4. 1. 1] are summarized and discussed in comparison with those of muscle phosphorylase b. They contain: 1) Purification and crystallization, 2) de novo Synthesis, 3) Molecular weight and amino acid composition, 4) Bound pyridoxal phosphate, 5) Circular dichroism, 6) Chemical modification. Although potato phosphorylase differs from muscle phosphorylase b in deter-mining enzyme activity, their molecular properties resemble each other in many respects which include molecular weight, amino acid composition, content and binding of pyridoxal phosphate, higher structure observed through circular dichroism, and specific amino acid residues directly involved in activity. It is also shown that primer is an absolute requirement for the synthesis of α-1, 4-glucan and no de nova synthesis occurs by phosphorylase.
