LOCALIZATION OF RHODOPSEUDOMONAS-VIRIDIS REACTION CENTER AND LIGHT HARVESTING PROTEINS USING FERRITIN-ANTIBODY LABELING

  • 1 January 1983
    • journal article
    • research article
    • Vol. 30  (1) , 1-8
Abstract
R. viridis thylakoid membrane polypeptides were characterized by SDS [sodium dodecyl sulfate] gels, 2 D gels and surface-specific iodination. Four polypeptides with apparent MW of 38,000, 33,000, 27,000 and 24,000 (reaction center) and 3 low MW polypeptides 11,000, 8000 and 6000 (probably light harvesting polypeptides) were identified. Antibodies were produced against the polypeptides eluted from SDS gels and tested for specificity by an immunoblotting assay. The antibodies were bound to the membranes and viewed by EM using a modification of the ferritin labeling technique. It is suggested that antigenic determinants for the 38,000, 33,000 and 27,000 reaction center polypeptides and the 11,000 and 8000 low MW polypeptides are present on the cytoplasmic membrane surface. The 33,000, 27,000, 11,000 and 6000 polypeptides appear to have surface-located residues which can be iodinated. The photosynthetic membrane of R. viridis appears to be a highly asymmetrical membrane.