Related Experiment Video
Updated: Jul 1, 2026

Single-Molecule Diffusion and Assembly on Polymer-Crowded Lipid Membranes
Published on: July 19, 2022
Significance of protein crowding, order and mobility for photosynthetic membrane functions
1Institute of Botany, Westfaelische-Wilhelms-Universität Münster, Schlossgarten 3, 48149 Münster, Germany. kirchhh@uni-muenster.de
Abstract:
Natural photosynthesis requires diffusion-based processes either for the functional communication of protein complexes or for the adaptation, maintenance and biogenesis of the photosynthetic apparatus. A conceptual problem with lateral diffusion in photosynthetic membranes arises from the fact that these membranes are densely packed with membrane integral protein complexes (molecular crowding). Theoretical analysis of PQ (plastoquinone) and protein diffusion in higher plant grana thylakoids reveal very inefficient lateral diffusion. In contrast, measurement of protein mobility in grana membranes shows that a fraction of protein complexes can move surprisingly fast. It is postulated that organization of protein complexes in supercomplexes and large-scale ordering of Photosystem II and light-harvesting complex II could be strategies for the optimization of diffusion in crowded thylakoid membranes.
More Related Videos
08:12Analysis of Thylakoid Membrane Protein Complexes by Blue Native Gel Electrophoresis
Published on: September 28, 2018
08:55Single-Molecule Imaging of Lateral Mobility and Ion Channel Activity in Lipid Bilayers using Total Internal Reflection Fluorescence (TIRF) Microscopy
Published on: February 17, 2023
Related Concept Videos
Protein Diffusion in the Membrane
Membrane Fluidity
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is a relatively...
Protein Transport to the Stroma
Protein complexes called the translocon of the outer chloroplast membrane or TOC complex, and the translocon of the inner chloroplast membrane or TIC complex mediate the...
Protein Transport to the Thylakoids
Protein Transport to the Inner Chloroplast Membrane
Protein Transport to the Outer Chloroplast Membrane
Two models describe the mechanism of precursor recognition and entry across the outer membrane through the TOC complex. Model 1 suggests the newly synthesized precursor binds to the TOC receptor 159 and forms a complex.