Polypeptide composition of thylakoid membranes from wild-type, TAM-2, and TAM-4 mutants. (a) Thylakoid pigment-protein complexes were separated by nondenaturing Deriphat PAGE upon solubilization with 1% β-DM. Thylakoids corresponding to 25 mg of chlorophylls were loaded in each lane. The composition of each band is indicated. (b) Immunoblotting used for the quantification of photosynthetic subunits in the wild-type (WT) and TAM thylakoids. Immunoblot analysis was performed with antibodies directed against individual gene products: LHCII, the major light harvesting complex of PSII; the PSII core subunit PsbC (CP43); the PSI core subunit (PsaA). Thylakoids corresponding to 0.25, 0.5, and 1 μg of Chls were loaded for each sample. All samples were loaded on the same SDS-PAGE slab gel. (c) Results of the immunotitration of thylakoid proteins. Data of PSII antenna subunits (left panel) and PSI core subunit (right panel) were normalized to the PSII core amount (PsbB content) and expressed as a percentage of the corresponding wild-type content ± SD. Significantly different values from wild type are marked with an asterisk.