Detection of calcium binding by photosystem II polypeptides immobilised onto nitrocellulose membrane

Photosystem II calcium‐binding polypeptides have been detected by their ability to selectively bind 45Ca when immobilised onto nitrocellulose membrane following SDS‐polyacrylamide gel electrophoresis. Two calcium‐binding polypeptides of 26 kDa and 24 kDa are shown to be components of LHCII. The 24 kDa polypeptide was further characterised by N‐terminal amino acid sequence analysis and shown to be the product of a type II cab gene. A third polypeptide of 33 kDa bound calcium more weakly and was not positively identified.