IMMUNOPURIFICATION OF A SUBCOMPLEX OF THE NAD(P)H-PLASTOQUINONE-OXIDOREDUCTASE FROM THE CYANOBACTERIUM SYNECHOCYSTIS SP PCC6803

An antibody against the NDH-K subunit of the NAD(P)H-dehydrogenase from the cyanobacterium Synechocystis sp. PCC6803 was used to isolate a subcomplex of the enzyme from Triton X- 100 solubilized total membranes by immunoaffinity chromatography. The isolated subcomplex consisted of seven major polypeptides with molecular masses of 43, 27, 24, 21, 18,14 and 7 kDa. The amino-terminal amino acid sequences of the polypeptides were determined. By comparing the sequences with the amino acid sequences deduced from DNA, three proteins were identified as NDH-H (43 kDa), NDH-K (27 kDa) and NDH-1 (24 kDa). A fourth subunit (NDH-J, 21 kDa) was identified by Western blot analysis with an NDH-J antibody.