Subcellular localization of a cytochrome P-450-dependent monogenase in vesicles of the higher plant Catharanthus roseus.

The intracellular location of a cytochrome P-450-dependent monoterpene hydroxylase from the higher plant, Catharanthus roseus, has been investigated. By differential and sucrose density gradient centrifugation, utilizing marker enzymes and electron microscopy, the monooxygenase was demonstrated to be associated with vesicles having a membrane thickness of 40-60 nm. The vesicles could be distinguished from endoplasmic reticulum, Golgi apparatus, mitochondria, and plasma membrane and were found in light membrane fractions containing provacuoles.