title: The Use of Contact Mode Atomic Force Microscopy in Aqueous Medium for Structural Analysis of Spinach Photosynthetic Complexes.
abstract: To investigate the dynamics of photosynthetic pigment-protein complexes in vascular plants at high resolution in an aqueous environment, membrane-protruding oxygen-evolving complexes (OECs) associated with photosystem II (PSII) on spinach (Spinacia oleracea) grana membranes were examined using contact mode atomic force microscopy. This study represents, to our knowledge, the first use of atomic force microscopy to distinguish the putative large extrinsic loop of Photosystem II CP47 reaction center protein (CP47) from the putative oxygen-evolving enhancer proteins 1, 2, and 3 (PsbO, PsbP, and PsbQ) and large extrinsic loop of Photosystem II CP43 reaction center protein (CP43) in the PSII-OEC extrinsic domains of grana membranes under conditions resulting in the disordered arrangement of PSII-OEC particles. Moreover, we observed uncharacterized membrane particles that, based on their physical characteristics and electrophoretic analysis of the polypeptides associated with the grana samples, are hypothesized to be a domain of photosystem I that protrudes from the stromal face of single thylakoid bilayers. Our results are interpreted in the context of the results of others that were obtained using cryo-electron microscopy (and single particle analysis), negative staining and freeze-fracture electron microscopy, as well as previous atomic force microscopy studies.
authors.affiliation: Department of Materials Science and Engineering (W.P., F.B.P.), Department of Mechanical Engineering (Z.H., F.B.P.), and Department of Biology (T.M.W.), Stanford University, Stanford, California 94305;Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (T.M.W., M.L.H., A.R.G.); andDepartment of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands (K.S., J.P.D., R.N.F.) phuthong@stanford.edu.
authors.forename: Witchukorn
authors.identifier: http://orcid.org/0000-0002-9811-3251
authors.initials: W
authors.lastname: Phuthong
authors.affiliation: Department of Materials Science and Engineering (W.P., F.B.P.), Department of Mechanical Engineering (Z.H., F.B.P.), and Department of Biology (T.M.W.), Stanford University, Stanford, California 94305;Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (T.M.W., M.L.H., A.R.G.); andDepartment of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands (K.S., J.P.D., R.N.F.).
authors.forename: Zubin
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Department of Materials Science and Engineering (W.P., F.B.P.), Department of Mechanical Engineering (Z.H., F.B.P.), and Department of Biology (T.M.W.), Stanford University, Stanford, California 94305;Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (T.M.W., M.L.H., A.R.G.); andDepartment of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands (K.S., J.P.D., R.N.F.).
authors.forename: Tyler M
authors.initials: TM
authors.lastname: Wittkopp
authors.affiliation: Department of Materials Science and Engineering (W.P., F.B.P.), Department of Mechanical Engineering (Z.H., F.B.P.), and Department of Biology (T.M.W.), Stanford University, Stanford, California 94305;Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (T.M.W., M.L.H., A.R.G.); andDepartment of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands (K.S., J.P.D., R.N.F.).
authors.forename: Kinga
authors.initials: K
authors.lastname: Sznee
authors.affiliation: Department of Materials Science and Engineering (W.P., F.B.P.), Department of Mechanical Engineering (Z.H., F.B.P.), and Department of Biology (T.M.W.), Stanford University, Stanford, California 94305;Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (T.M.W., M.L.H., A.R.G.); andDepartment of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands (K.S., J.P.D., R.N.F.).
authors.forename: Mark L
authors.initials: ML
authors.lastname: Heinnickel
authors.affiliation: Department of Materials Science and Engineering (W.P., F.B.P.), Department of Mechanical Engineering (Z.H., F.B.P.), and Department of Biology (T.M.W.), Stanford University, Stanford, California 94305;Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (T.M.W., M.L.H., A.R.G.); andDepartment of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands (K.S., J.P.D., R.N.F.).
authors.forename: Jan P
authors.initials: JP
authors.lastname: Dekker
authors.affiliation: Department of Materials Science and Engineering (W.P., F.B.P.), Department of Mechanical Engineering (Z.H., F.B.P.), and Department of Biology (T.M.W.), Stanford University, Stanford, California 94305;Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (T.M.W., M.L.H., A.R.G.); andDepartment of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands (K.S., J.P.D., R.N.F.).
authors.forename: Raoul N
authors.initials: RN
authors.lastname: Frese
authors.affiliation: Department of Materials Science and Engineering (W.P., F.B.P.), Department of Mechanical Engineering (Z.H., F.B.P.), and Department of Biology (T.M.W.), Stanford University, Stanford, California 94305;Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (T.M.W., M.L.H., A.R.G.); andDepartment of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands (K.S., J.P.D., R.N.F.).
authors.forename: Fritz B
authors.initials: FB
authors.lastname: Prinz
authors.affiliation: Department of Materials Science and Engineering (W.P., F.B.P.), Department of Mechanical Engineering (Z.H., F.B.P.), and Department of Biology (T.M.W.), Stanford University, Stanford, California 94305;Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305 (T.M.W., M.L.H., A.R.G.); andDepartment of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands (K.S., J.P.D., R.N.F.).
authors.forename: Arthur R
authors.initials: AR
authors.lastname: Grossman
mesh_terms: D007089:Image Enhancement / Q000379:methods; D018625:Microscopy, Atomic Force / Q000379:methods*; D046912:Multiprotein Complexes / Q000032:analysis* / Q000737:chemistry; D045332:Photosystem II Protein Complex / Q000032:analysis* / Q000737:chemistry; D018724:Spinacia oleracea / Q000737:chemistry* / Q000378:metabolism; D020524:Thylakoids / Q000737:chemistry / Q000378:metabolism
chemical_list: D046912:Multiprotein Complexes; D045332:Photosystem II Protein Complex