title: A quantitative secondary structure analysis of the 33 kDa extrinsic polypeptide of photosystem II by FTIR spectroscopy.
abstract: In chloroplast photosystem II, the extrinsic polypeptide of 33 kDa is involved in the stabilization the Mn cluster in charge of water splitting and in the fulfilment of the Ca(2+)-cofactor requirement for oxygen evolution. The conformational analysis of the purified 33 kDa extrinsic polypeptide was carried out using FTIR spectroscopy with its self-deconvolution and second derivative resolution enhancement as well as curve-fitting procedures. The FTIR spectroscopic results showed that the isolated polypeptide is characterized by a major proportion beta-sheet conformation (36%) with 27% alpha-helix, 24% turn, and 13% beta-antiparallel structures.
authors.affiliation: Centre de recherche en photobiophysique, Université du Québec a Trois-Rivières, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Ahmed
authors.forename: H A
authors.initials: HA
authors.lastname: Tajmir-Riahi
authors.forename: R
authors.initials: R
authors.lastname: Carpentier
mesh_terms: D002118:Calcium / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D008345:Manganese / Q000737:chemistry; D008970:Molecular Weight; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry*; D045332:Photosystem II Protein Complex; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017550:Spectroscopy, Fourier Transform Infrared; D014867:Water / Q000378:metabolism
chemical_list: D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D014867:Water; D008345:Manganese; D002118:Calcium