Exopolygalacturonate Lyase Produced by Streptomyces massasporeus

抄録

An exopolygalacturonate lyase (EC 4.2.2.9) was purified to a homogeneous state from the culture filtrate of Streptomyces massasporeus. The molecular weight was estimated to be about 54000 and the isoelectric point was pH 5.5. The enzyme was most active at pH 9.5 and 40°C, and was relatively stable at pH 3.0 to 10.0 (at 2°C for 72 hr) and below 50°C (at pH 7.0 for 10 min). Ca²⁺ was required for maximum activity. The enzyme was most active on trigalac-turonic acid and had higher activity on low methoxyl pectins rather than on polygalacturonic acid. The enzyme removed terminal unsaturated digalacturonate units from the galacturonide chains.