Membrane Protein Purification in Nanodiscs

Alpha Lifetech Inc. focuses on recombinant proteins' expression in different Biosystems for many years, including cell-based and cell-free organisms. 


Membrane Protein Purification Based on Nanodiscs Technology


To purify membrane protein in a native-like form and a condition without detergent, Alpha Lifetech Inc. developed the most up-to-date platform, Nanodiscs technology, to cooperate with the cell-free systems for soluble recombinant protein purification. Nanodiscs technology involves three parts in membrane protein purification: expression of target proteins (membrane proteins, MPs), soluble nanoscale phospholipid bilayers, and membrane scaffold proteins (MSPs).

Target proteins: integral or part of membrane protein expressed in cell-free systems and can be modified with different tags such as biotinylation or isotope labelling.

PBs: amphipathic phospholipid bilayers, dimyristoyl-glycero-phosphocholine (DMPC) and palmitoyl-oleoyl-phosphatidylcholine (POPC) are most often used as PBs, which can self-assemble integral membrane proteins for biophysical, enzymatic or structural investigations.

MSPs: membrane scaffold proteins, truncated forms of apolipoprotein (Apo) A-I which wrap around a patch of a lipid bilayer to form a disc-like particle or nanodisc. And MSPs are often linked by 6x His tag, which means they can be easily purified or immobilized in a detergent-free condition. 

Nanodiscs, the nanoscale systems (the average size from 9 to 17 nm) with self-assembling ability, can stabilize membrane proteins extracted from the membrane with surfactants. Nanodiscs can also provide a phospholipid bilayer system maintained by the amphipathic membrane scaffold proteins (MSPs) (Figure 1), which are truncated forms of human apolipoprotein A-I (apo A-I) that wrap around the hydrophobic core of the lipids to form a disc-like particle.

Fig. 1 the Schematic of Proteins Expressed in Nanodisc Form 

Applications of Proteins Crapped in Nanodisc Systems: Table 1

Binding studies of agonist, antagonist and radiolabel exchange in G proteins

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS)

Nuclear magnetic resonance (NMR)

Protein phosphorylation/activation studies

Surface plasmon resonance (SPR)

Electron microscopy (EM)

Resonance Raman spectroscopy

Time-resolved fluorescence spectroscopy

Cryo-electron microscopy (EM)

Solid-state NMR

Radioligand binding/scintillation proximity assay

NMR analysis of lipid-interacting, soluble proteins


In addition, Alpha Lifetech Inc. can yield recombinant proteins in cell-based systems, such as Mammal Expression System, Insect Expression System, Bacteria Expression System and Yeast Expression System. We can express the recombinant protein in a detergent form or detergent-free form (24 detergents). For more information, please feel free to contact us at any time.