Thylakoid membrane polypeptides of Chlamydomonas reinhardtii: wild-type and mutant strains deficient in photosystem II reaction center.

摘要: Unstacked thylakoid membrane vesicles were obtained from a homogenate of Chlamydomonas reinhardtii by flotation in 1.8 M sucrose layer containing 5 mM HEPES (N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid)-10 EDTA (pH 7.5). Sodium dodecyl sulfate-gradient gel electrophoresis showed that the wildtype membranes have total at least 33 polypeptides ranging molecular weights 68,000 to less than 10,000. The wild-type and three non-photosynthetic mutant strains studied with respect their photosynthetic electron transport properties, fluorescence rise kinetics, polypeptide compositions. results strong correlation between presence (molecular weight = 47,000) activity photosystem II reaction center. This is missing F34 (a mendelian lacking Q, primary acceptor II), but partially restored suppressed strain which there an incomplete recovery activity. In thermosensitive mutant, T4, same present reduced amount only cells grown 35 degrees not those 25 degrees. Evidence kinetics partial photochemical reactions show degree are similar greatly deficient Q.