title: The 33 kDa protein of photosystem II is a low-affinity calcium- and lanthanide-binding protein.
abstract: We have shown that the isolated 33 kDa protein of photosystem II contains one calcium and one lanthanide low-affinity binding site with binding constants (K(D)) on the order of 10(-5) M. Binding of calcium or lanthanides to this site induces conformational changes in the protein that manifest in fluorescence emission spectra of the protein, circular dichroism spectra, and calorimetric thermograms where the phase transitions are shifted to lower temperatures. The role of calcium binding to the 33 kDa protein in the attainment of its native structure and the significance of this interaction for the oxygen evolution process are discussed.
authors.affiliation: Department of Plant Physiology and Biochemistry, Faculty of Biotechnology, Jagiellonian University, ul. Gronostajowa 7, 30-387 Kraków, Poland. jkruk@mol.uj.edu.pl
authors.forename: Jerzy
authors.initials: J
authors.lastname: Kruk
authors.forename: Kvetoslava
authors.initials: K
authors.lastname: Burda
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Jemioła-Rzemińska
authors.forename: Kazimierz
authors.initials: K
authors.lastname: Strzałka
mesh_terms: D001665:Binding Sites; D002135:Calcium-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D002152:Calorimetry, Differential Scanning; D002942:Circular Dichroism; D004419:Dysprosium / Q000378:metabolism; D005063:Europium / Q000378:metabolism; D028581:Lanthanoid Series Elements / Q000378:metabolism*; D008024:Ligands; D008970:Molecular Weight; D045332:Photosystem II Protein Complex / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence; D018724:Spinacia oleracea; D013816:Thermodynamics
chemical_list: D002135:Calcium-Binding Proteins; D028581:Lanthanoid Series Elements; D008024:Ligands; D045332:Photosystem II Protein Complex; D004419:Dysprosium; D005063:Europium