Solubilization and reconstitution of the membrane-bound carotenogenic enzymes from daffodil chromoplasts

Abstract

The membrane-bound carotenogenic enzymes of daffodil (Narcissus pseudonarcissus) chromoplast membranes, i.e. dehydrogenation, cis-trans isomerization and cyclization activities, were solubilized in an enzymatically inactive form using the zwitterionic detergent 3-[(3-cholamidopropyl)-dimethylamino]-1-propanesulfonate (Chaps). Full enzymatic activities were regained upon reconstitution of the solubilized proteins into liposomes. These preparations converted radiolabelled cis-phytoene into beta-carotene in a high yield. The reconstituted enzymatic sequence behaved as a tight 'assembly line'. In the enzymatic sequence of the reconstituted system the cis-trans isomerization reaction occurred on the stage of cis-phytofluene after a dehydrogenation of cis-phytoene.