The chlorophylla/b‐proteins of PS I and PS II are immunologically related

Abstract
Polyclonal antisera were raised against three apoproteins of the light‐harvesting chlorophylla/b‐protein complex of photosystem I (LHC I) from spinach. These antisera were found to cross‐react with all four LHC I and both LHC II apoproteins on immunoblots. Affinity purification of the cross‐reactive antibodies on either the ‘native’ LHC II complex or on the 28 kDa apoprotein of LHC II immobilized on nitrocellulose yielded antibodies which recognize the same apoproteins as the crude sera. Partial peptide mapping of LHC I and LHC II apoproteins withStaphylococcus aureusV8 protease andN‐chlorosuccinimide showed different patterns for each polypeptide. These data demonstrate that the four polypeptides of LHC I are distinct from each other and from the two major polypeptides of LHC II but all six are immunologically related.