Role of Protein-Water Interface in the Stacking Interactions of Granum Thylakoid Membranes—As Revealed by the Effects of Hofmeister Salts
Journal Article
·
· Frontiers in Plant Science
- Biological Research Centre, Szeged (Hungary)
- Centre for Energy Research, Budapest (Hungary)
- Paul Scherrer Inst. (PSI), Villigen (Switzerland); Wigner Research Centre for Physics, Budapest (Hungary); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Forschungszentrum Juelich, Garching (Germany)
- Paul Scherrer Inst. (PSI), Villigen (Switzerland)
- Biological Research Centre, Szeged (Hungary); Univ. of Ostrava (Czechia)
The thylakoid membranes of vascular plants are differentiated into stacked granum and unstacked stroma regions. The formation of grana is triggered by the macrodomain formation of photosystem II and light-harvesting complex II (PSII-LHCII) and thus their lateral segregation from the photosystem I—light-harvesting complex I (PSI-LHCI) super-complexes and the ATP-synthase; which is then stabilized by stacking interactions of the adjacent PSII-LHCII enriched regions of the thylakoid membranes. The self-assembly and dynamics of this highly organized membrane system and the nature of forces acting between the PSII-LHCII macrodomains are not well understood. By using circular dichroism (CD) spectroscopy, small-angle neutron scattering (SANS) and transmission electron microscopy (TEM), we investigated the effects of Hofmeister salts on the organization of pigment-protein complexes and on the ultrastructure of thylakoid membranes. We found that the kosmotropic agent (NH4)2SO4 and the Hofmeister-neutral NaCl, up to 2 M concentrations, hardly affected the macro-organization of the protein complexes and the membrane ultrastructure. In contrast, chaotropic salts, NaClO4, and NaSCN destroyed the mesoscopic structures, the multilamellar organization of the thylakoid membranes and the chiral macrodomains of the protein complexes but without noticeably affecting the short-range, pigment-pigment excitonic interactions. Comparison of the concentration- and time-dependences of SANS, TEM and CD parameters revealed the main steps of the disassembly of grana in the presence of chaotropes. It begins with a rapid diminishment of the long-range periodic order of the grana membranes, apparently due to an increased stacking disorder of the thylakoid membranes, as reflected by SANS experiments. SANS measurements also allowed discrimination between the cationic and anionic effects—in stacking and disorder, respectively. This step is followed by a somewhat slower disorganization of the TEM ultrastructure, due to the gradual loss of stacked membrane pairs. Occurring last is the stepwise decrease and disappearance of the long-range chiral order of the protein complexes, the rate of which was faster in LHCII-deficient membranes. These data are interpreted in terms of a theory, from our laboratory, according to which Hofmeister salts primarily affect the hydrophylic-hydrophobic interactions of proteins, and the stroma-exposed regions of the intrinsic membrane proteins, in particular—pointing to the role of protein-water interface in the stacking interactions of granum thylakoid membranes.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- Czech Science Foundation; Hungarian Academy of Sciences; Hungarian Ministry for Innovation and Technology; Ministry for National Economy of Hungary; National Research Development and Innovation Office of Hungary; USDOE
- Grant/Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1747014
- Journal Information:
- Frontiers in Plant Science, Journal Name: Frontiers in Plant Science Vol. 11; ISSN 1664-462X
- Publisher:
- Frontiers Research FoundationCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Fine Mapping and Identification of BnaC06.FtsH1, a Lethal Gene That Regulates the PSII Repair Cycle in Brassica napus
|
journal | February 2021 |
Similar Records
The structural and functional domains of plant thylakoid membranes
Anisotropic Circular Dichroism Signatures of Oriented Thylakoid Membranes and Lamellar Aggregates of LHCII
Anisotropic Circular Dichroism Signatures of Oriented Thylakoid Membranes and Lamellar Aggregates of LHCII
Journal Article
·
Thu Oct 11 20:00:00 EDT 2018
· The Plant Journal
·
OSTI ID:1735375
Anisotropic Circular Dichroism Signatures of Oriented Thylakoid Membranes and Lamellar Aggregates of LHCII
Journal Article
·
Sun Jun 12 00:00:00 EDT 2011
· Photosynthesis Research
·
OSTI ID:1040578
Anisotropic Circular Dichroism Signatures of Oriented Thylakoid Membranes and Lamellar Aggregates of LHCII
Journal Article
·
Wed Feb 29 23:00:00 EST 2012
· Photosynthesis Research
·
OSTI ID:1044016