molecular dynamics simulations of PR3 anchored at three different phospholipid bilayers: dimyristoylphosphatidylcholine DMPC and dimyristoylphosphatidylglycerol DMPG, and an equimolar mixture of DMPC/DMPG. Basic residues R177, R186A, R186B, K187 and R222 interact via hydrogen bonds with the lipid headgroups to stabilize PR3 at the interfacial membrane region. Hydrophobic amino acids V163, F165, F166, I217, L223, and F224 insert into the hydrophobic core below the carbonyl groups of the bilayers and aromatic amino acids F165, F192, F215, W218, F224, and F227 contribute electrostatic interaction via cation-pi interactions with the choline groups of DMPC. PR3 presents all the characteristics of a peripheral membrane protein with an ability to bind negative phospholipids. The catalytic triad remains unperturbed by the presence of the membrane, the ligand binding sites are located in close proximity to the membrane and amino acids K99 and I217 interact significantly with the lipids |
Homo sapiens |