Nanodisc technology is an approach to render membrane proteins soluble in aqueous solutions in a native-like bilayer environment, where the membrane proteins remain stable and active. The Nanodisc concept is derived from high density lipoprotein (HDL) particles and their primary protein component, apolipoprotein. The Nanodisc is a non-covalent structure of phospholipid bilayer and membrane scaffold protein (MSP), a genetically engineered protein, which mimics the function of Apolipoprotein A-1 (ApoA-1).
The first MSP, MSP1, was engineered with its sequence based on the sequence of A-1, but without the globular N-terminal domain of native A-1. The Membrane Scaffold Protein 1D1 (MSP1D1) variant of MSP1 deletes the first 11 amino acids in the Helix 1 portion (referred to as “H0.5” in the accompanying figure) of the original MSP1 sequence. The D73C variant of MSP1D1 (MSP1D1 D73C) substitutes a cysteine (C) for an aspartic acid (D) at position 73 of the original native A-1 sequence, within the Helix 2 segment (H2) of the protein.
