title: Effects of Pb2+ on the structure and function of photosystem II of Spirodela polyrrhiza.
abstract: Lead (Pb(2+)) is a well-known highly toxic element, and Spirodela polyrrhiza is one of the hydrophytes most sensitive to Pb(2+), which might be highly toxic to photosynthesis. However, the mechanism by which Pb(2+) inhibits energy transfer and conversion efficiency remains unclear. Here, we report the effects of Pb(2+) on the secondary structure and function of photosystem II (PS II) of S. polyrrhiza using spectral methods. We found that Pb(2+) accumulated in PS II and damaged its secondary structure, decreased the absorbance of visible light, inhibited energy transfer among amino acids within the PS II protein-pigment complex, and reduced energy transport from tyrosine residue to chlorophyll a. Taken together, Pb(2+) exposure damaged the structure and function of S. polyrrhiza PS II.
authors.affiliation: Medical College of Suzhou University, Suzhou, People's Republic of China.
authors.forename: Ling
authors.initials: L
authors.lastname: Qufei
authors.forename: Hong
authors.initials: H
authors.lastname: Fashui
mesh_terms: D029064:Araceae / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism*; D002942:Circular Dichroism; D004735:Energy Transfer / Q000187:drug effects; D007854:Lead / Q000737:chemistry / Q000494:pharmacology*; D010100:Oxygen / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000737:chemistry* / Q000378:metabolism*; D017433:Protein Structure, Secondary / Q000187:drug effects; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
chemical_list: D045332:Photosystem II Protein Complex; D007854:Lead; D010100:Oxygen