Starch Phosphorylase: Biochemical and Biotechnological New Perspectives

A dynamic mediatory role between starch synthesis and degradation has been ascribed to starch
phosphorylase. However, plant starch phosphorylase is largely considered to be involved in
phosphorolytic degradation of starch. It reversibly catalyzes the transfer of glucosyl units from
glucose-1-phosphate to the non-reducing end of glucan chain with the release of inorganic phosphate.
It is widely distributed in plant kingdom. Enzyme multiplicity is also common in starch phosphorylase
and different multiple forms have been predicted to have different roles in starch metabolism. Here,
various biochemical properties have been reviewed. Its regulation by aromatic amino acids has also
been discussed. Importance of plastidial and cytoplasmic starch phosphorylase has also been
discussed. Various biotechnological aspects have been discussed. Its exploitation in production of
glucose-1-phosphate, a cytostatic compound has been discussed in the present review.