Lipoparticle Technology

Lipoparticles are non-infectious virus-like particles (VLPs) containing high concentrations of specific membrane proteins in their native conformation.

Lipoparticles typically contain 50-200 pmol/mg of a specific target membrane protein, which corresponds to approximately 50-200 specific receptors per Lipoparticle. Membrane protein incorporation is directly related to the amount of the membrane protein expressed at the cell surface.

Yes, target membrane proteins are conformationally-intact because they are incorporated onto the surface of Lipoparticles directly from the cell surface and are never extracted or refolded. Lipoparticles are usually produced from human cell lines so receptors also contain native post-translational modifications. Conformational integrity is demonstrated using conformation-dependent antibodies or ligand binding, depending on the receptor and available reagents.

Yes, two or more membrane proteins can be incorporated simultaneously while maintaining their association as multi-protein complexes.

Lipoparticle stability is comparable to other purified proteins. Lipoparticles are stable for at least 6 months when refrigerated or frozen. Like most lipid structures, Lipoparticles will be disrupted by detergents, but are stable in the presence of small amounts (<5%) of common additives (e.g. DMSO, ethanol). Lipoparticle suspensions will appear as an opaque solution and should be gently mixed prior to use. Excessive vortexing, dilution, and filtration of Lipoparticles should be avoided to minimize sample loss.

Lipoparticles are non-living biochemical reagents, so can readily be modified during the production and purification process. Lipoparticles are available from Integral Molecular biotinylated or fluorescently labeled.

Lipoparticles bud from the cell surface, so they contain specific membrane proteins of interest as well as additional membrane proteins from the cells used for production. The effects of non-specific membrane proteins are minimized by over-expression of the membrane protein of interest, the use of alternative cell types where necessary, and the use of Null Lipoparticles that do not contain the membrane protein of interest as negative controls.