Lipid - Protein Interactions
Membrane are the barriers to cells and organelles that are made up of a diverse set of lipids. To add to this complexity, different organisms, cells and organelles have different lipid compositions. Membrane proteins are solvated and interact with the lipids within the membrane. However, which lipids a membrane protein is solvated by, a representation of the bulk mixture or a specific subset, is unknown. In addition, what the energetics and molecular basis for these interactions is not fully understood. Identifying lipid – protein interactions is a challenge due to the inability to capture the local lipid environment without disrupting the interactions. Quantifying these interactions is a challenge because systems to date are not easily titratable and, therefore, are not able to obtain thermodynamic information about the lipid – protein interactions.
We are developing several approaches to quantify and identify lipid -lipid and lipid - protein interactions.
The fluidity of phosphocholine and maltoside micelles and the effect of CHAPS.
Kieber M, Ono T, Oliver RC, Nyenhuis, SB, Ashtari M, Tieleman DP, Columbus L
Biophysical Journal. 116:1682 – 1691 (2019). PMC6506624
Low q bicelles are mixed micelles.
Caldwell T*, Baoukina S*, Brock A, Oliver RC, Glover KJ, Tieleman DP, Columbus L
Journal of Physical Chemistry Letters. 9:4469 – 4473 (2018). PMC6353637
Tuning micelle dimensions and properties with binary surfactant mixtures.
Oliver RC, Lipfert, Fox DA, Lo RH, Kim JJ, Doniach S, Columbus L.
Langmuir.30:13353 – 13361 (2014).
Mapping membrane protein dynamics: a comparison of site-directed spin labeling to NMR 15N-relaxation measurements.
Lo RH, Kroncke BM, Solomon T, Columbus L.
Biophysical Journal.107:1697 – 1702 (2014). PMC4190660