Purification of (+)-delta-cadinene synthase, a sesquiterpene cyclase from bacteria-inoculated cotton foliar tissue.

A sesquiterpene cyclase whose activity is induced in a glandless, bacterial blight-resistant line of cotton (Gossypium hirsutum L.) catalyses the conversion of (E,E)-farnesyl diphosphate to (+)-delta-cadinene. This enzyme was purified by a combination of salt-induced phase separation, hydroxylapatite fractionation, hydrophobic interaction and strong anion-exchange chromatography, and denaturing polyacrylamide gel electrophoresis, followed by renaturation with Tween 80. The purified enzyme has a molecular weight of 64-65 kDa, and exhibited a single silver-staining band following electrophoresis in analytical denaturing polyacrylamide gels. Amino acid sequences of three tryptic peptides from the enzyme have been determined and are similar to known sequences in other terpene cyclases from plants.