title: Substrate transfer in carotene biosynthesis in Phycomyces.
abstract: Lycopene cyclization to gamma-carotene and then to beta-carotene is partially blocked in Phycomyces by the presence of car R mutations in heterokaryosis or by the addition of 2-(4-chlorophenyl)thiotriethylamine . HCl to the medium. We have quantitatively determined the carotenes synthesized by Phycomyces under conditions of partially blocked cyclization and in the presence of either car A mutations in heterokaryosis or polyoxyethylenesorbitan monooleate (Tween-80) in the medium. We conclude that transfer of intermediate substrates between the enzyme aggregates involved in carotenogenesis does occur in the wild type but not in heterokaryons for car A mutations, and is facilitated by Tween-80.
mesh_terms: D002338:Carotenoids / Q000096:biosynthesis* / Q000378:metabolism; D055598:Chemical Phenomena; D002621:Chemistry; D003500:Cyclization; D005658:Fungi / Q000378:metabolism*; D000077276:Lycopene; D009154:Mutation; D010800:Phycomyces / Q000235:genetics / Q000378:metabolism*
chemical_list: D002338:Carotenoids; D000077276:Lycopene