TITLE : Plant Thylakoid Polymorphism and Dynamical Heterogeneity

ABSTRACT :

Chlorophyll (CLA) binding light harvesting complex II (LHCII) and thylakoid membranes are essential for photosynthesis in plants. To investigate how CLA and LHCII influence the structure and dynamics of thylakoid membranes, coarse-grained molecular dynamics (CG MD) simulations using MARTINI-2 force fields are conducted at 293 K, varying the CLA and lipid concentrations. The simulations reveal that above a critical CLA concentration, the thylakoid membranes undergo a transition from a lamellar to a non-lamellar phase and LHCII resist the polymorphism. CLA molecules tend to aggregate into structures of varying orders and attract non-bilayer forming lipids with fewer unsaturated bonds, leading to a non-lamellar phase characterized by fused membrane regions. These fused areas cause structural immobilization of CLA and lipids and introduce dynamical heterogeneity, as evidenced by non-Gaussian parameters and van Hove correlation functions. This transition from lamellar to non- lamellar phases is associated with a significant decrease in the correlation length of immobile CLA and lipids due to the fused membrane topology. Understanding these CLA-induced structural transitions can be extended and applied to LHCII induced thylakoid phase transitions for studying non-photochemical quenching mechanisms and offers potential for developing artificial photosynthetic materials and applications in photodynamic therapy.

MEETING DETAILS :

Speaker: Prof. Ananya Debnath (Department of Chemistry, IIT Jodhpur)

Venue: SC-NKN, South Campus, IIT Mandi

Date and Time: Friday, 12 Dec 2024 3:00 pm(IST)