Effect of membrane thickness on conformational sampling of phospholamban from computer simulations.
The conformational sampling of monomeric, membrane-bound phospholamban is described from computer simulations. Phospholamban (PLB) plays a key role as a regulator of sarcoplasmic reticulum calcium ATPase. An implicit membrane model is used in conjunction with replica exchange molecular dynamics simulations to reach mus-ms timescales. The implicit membrane model was also used to study the effect of different membrane thicknesses by scaling the low-dielectric region. The conformational sampling with the membrane model mimicking dipalmitoylphosphatidylcholine bilayers is in good agreement overall with experimental measurements, but consists of a wide variety of different conformations including structures not described previously. The conformational ensemble shifts significantly in the presence of thinner or thicker membranes. This has implications for the structure and dynamics of PLB in physiological membranes and offers what we believe to be a new interpretation of previous experimental measurements of PLB in detergents and microsomal membrane.
Sayadi
Maryam
M
Department of Chemistry, Michigan State University, East Lansing, USA.
Tanizaki
Seiichiro
S
Feig
Michael
M
D002135:Calcium-Binding Proteins / Q000737:chemistry*; D002462:Cell Membrane / Q000737:chemistry*; D003198:Computer Simulation; D008954:Models, Biological; D017433:Protein Structure, Secondary; D013816:Thermodynamics; D000099211:Phospholamban
D002135:Calcium-Binding Proteins; D000099211:Phospholamban