Nanoxis (www.nanoxis.com), a Swedish biotechnology company working on developing tools for the study and analysis of membrane proteins, launched its first commercial product for membrane protein sample preparation. Developed for use in the characterization and identification of membrane proteins using MS workflow, the LPI™ (lipid-based protein immobilization) SamplePrep kit is based on the company’s detergent-free LPI technology.
The LPI technology allows researchers to generate lipid bilayer vesicles from cell preparations and immobilize them on a patented support. Both membrane and transmembrane proteins, including ion channels and GPCRs, are thus available in their native state for subsequent digestion and analysis.
The kit is composed of the LPI FlowCell, designed as a single-use reaction chamber on which the lipid vesicles are bound, together with a FlowCell Holder, reagent set, and certified enzymes for protein digestion performed in the FlowCell.
The FlowCell accepts membrane vesicles derived from synthetic hosts, mammalian cell lines, bacteria, and yeast, as well as organelle-derived vesicles. Because the proteins are held in their native state, physical or chemical modifications, such as labeling or digestion, result in no loss or dilution of sample, explains Nanoxis CEO Ahmet Senoglu.
“We believe LPI could become an industry standard in the field of membrane protein analysis,” Senoglu claims. “Compared with gel- or detergent-based approaches, LPI results in higher sensitivity and lower sample loss, dramatically reducing the number of MS analyses required by a factor of 10 or more.”
With 60–70% of all drugs currently on the market targeting membrane proteins, the importance of such targets in disease pathways and thus as targets for drug development is evident, Nanoxis points out.
The LPI technology is based on research by professor Owe Orwar’s group at Chalmers University of Technology (www.orwarlab.mc2.chalmers.se). Nanoxis was established in 2002 specifically to further develop and commercialize the related IP. Prior to the launch of the LPI SamplePrep kit, the company offered the technology as a fee-based contract research service.
“Our work with research, pharma, and biotech clients, including GlaxoSmithKline(www.gsk.com) and AstraZeneca(www.astrazeneca.com), provided useful insights into the industry’s requirements in the area of membrane protein analysis,” explains Anders Karlsson, Ph.D., Nanoxis senior scientist. “While LPI SamplePrep is the first commercial kit to be developed using LPI, we also plan to develop a range of additional products based on this versatile technology.”
Through its work with industry clients, Nanoxis has primarily been applying the LPI technology for membrane protein profiling or sequence coverage studies. “Using our technology, we can, for example, compare expression levels of membrane proteins in cells in different disease states or subjected to different drugs or environmental conditions,” states Dr. Karlsson.
“Moreover, because LPI results in no sample loss or dilution, the technology is ideally suited to sequence coverage studies. We have developed a sequential digest protocol specifically designed for this purpose. In the protocol, proteases are added to the immobilized preparations, and then after the first digests have been collected for analysis, another round of digestion can be performed and so on.
“Alternatively,” concludes Dr. Karlsson, “we can sequentially use a number of different proteases on the same sample, which essentially shaves off peptides, to optimize the sequence coverage.”
Future products planned by Nanoxis will complement the kit by allowing additional separation steps or more detailed membrane protein studies, including protein-protein interaction and protein-binding analysis, combined with detailed analysis of subunits within complex membrane proteins, ion channels, or low-abundance proteins.
While Nanoxis is now focused on building its consumables business, the company aims to continue working on a contract or partnership basis with companies globally.