Most of the ADP-glucose pyrophosphorylases from different sources are stable to a heat treatment. We found that in the potato (Solanum tuberosum L.) tuber enzyme, the intermolecular disulfide bridge located between Cys12 of the small subunits is responsible for the stability at 60°C. When this unique disulfide bond is cleaved the enzyme is stable up to 40°C. Mutation of Cys12 in the small subunit into either Ala or Ser yielded enzymes with stability similar to the reduced form of the wild type. Concurrently, the enzyme with a truncated small subunit on the N-terminal was stable only up to 40°C. Thus, the N-terminal is important for the stability of the enzyme because of the presence of a disulfide bond.
|Number of pages
|Biochemical and Biophysical Research Communications
|Published - Apr 21 1999
ASJC Scopus subject areas
- Molecular Biology