Hold on to your membrane protein

By Nanoxis

Membrane proteins are hard to handle. Deadlines are constantly broken, research budgets stretched to the limit and not to mention the overall general frustration. Nevertheless, despite the many bottlenecks, membrane proteins cannot be neglected; they are far too important and play a vital role in biology. New products that will bypass the bottlenecks in membrane protein research are in high demand; Nanoxis intends to meet this demand.

The inherent nature of membrane proteins being dependent on a hydrophobic surrounding is associated with several challenges. These challenges will inevitably include sample isolation and preparation generally identified at an early stage in the research agenda. Advancement in membrane proteomics in order to overcome difficulties is highly desired and new technologies entering the scene are both prosperous and welcomed. Nanoxis has the technology, knowledge and aspiration to advance the membrane proteomics field. This is achieved by offering innovative and precious products, which can be of use in several important areas such as cancer, diabetes, drug discovery and stem cell research.

Currently the proteomic field lacks standardized methods, procedures and generalized workflows in order to handle the vast complexity of generated data. Scrutinizing the proteomics workflow, generated data for peptide/protein identification will depend on sample processing, peptide fractionation, instruments of choice, search-engines and databases. The number of methods and protocols are huge and far from standardized. Standardizing the proteomic workflow and data handling is a must do for the research community, the sooner the better.

Nanoxis was founded in 2002 as a spin-off company from Prof. Owe Orwar´s research group at Chalmers University of Technology. Nanoxis’ products are based on a technology which immobilizes functional membrane proteins with retained natural lipid composition. The Lipid-based Protein Immobilization (LPI™) technology was developed in cooperation with academic groups and pharmaceutical companies. To meet the market demand, Nanoxis launched the first product in 2006. Currently, Nanoxis’ products are aimed at applications which require immobilization of the membrane protein(s) of interest. Existing customers can be found evenly spread between academia and industry and in many different research fields. The products of today are sold as ready-to-use kits and immobilization of membrane proteins is done in a few easy steps. The main application is the study of protein/peptide composition of various biological membranes. The sample is immobilized as small lipid vesicles; proteoliposomes. Proteoliposomes are then treated with proteases to generate peptides which can be analysed by LC-MS/MS.

Membrane protein research as simple as one, two, three: Isolate, vesiculate and immobilize.

New applications are currently being developed following the success of the present one. The fact that the LPI™ technology is capable of immobilizing membrane proteins directly from their natural source opens up for several diverse applications. The LPI™ technology has a promising future in the search for new antibodies using either phage display against immobilized target or by the search for epitopes exposed on the extra cellular parts of membrane proteins. Since fluid can easily be exchanged over the LPI™ FlowCell surface it is ideal for multi step protease treatment, identification of posttranslational modifications, membrane protein topology and ligand binding to name but a few.

Assistant Professor Roger Karlsson, Department of Chemistry, University of Gothenburg, makes use of the LPI TM technology in the study of bacterial membrane proteins. Of special interest is the proteome of surface exposed proteins of bacteria, the so called “surfaceome”. One challenging task for Dr. Karlsson and co-workers, besides developing protocols for membrane isolation, is the use of intact bacteria together with the LPI TM technology to study the surfaceome.

“The LPI TM technology has enabled us to find previously unknown and unique membrane proteins in the anaerobic ammonium oxidizing (anammox) bacteria. Another project in which the LPI TM technology is used concerns the outer membrane proteins of the human pathogens Helicobacter pylori and Salmonella Typhimurium. The outer membrane proteins are the key to understand host – pathogen interactions and are also attractive targets to improve antibody selection. The membrane proteins are immobilized in their native membrane in the FlowCell and therefore the exposed parts of the membrane proteins are easily identified, thus making the process of target identification for vaccine development easy and rapid. Another strong point is that the LPI TM technology is very flexible when it comes to sample type – membrane preparations from yeast, bacteria and mammalian cells or even intact bacteria have now been tested successfully.” Preliminary results look very promising, says Assistant Professor Roger Karlsson.

The market potential is large and, most importantly, rapidly growing for products addressing membrane protein research. The market for products targeting soluble proteins is large and well recognized. According to estimates [1], the current market aimed at membrane proteins only constitutes of a small fraction. However, membrane proteomics will contribute significantly to the future growth of the whole proteomics field. It is estimated [2] that as much as 2/3 of all future drugs will target membrane proteins. If the current bottlenecks in membrane protein research are passed, more companies and academic research institutes will step with confidence into the prosperous and flourishing field of membrane protein research.

The amount of data generated by old and new technologies will contribute to the understanding of the proteome, but data is not knowledge. To generate – and perhaps most importantly, convert – data into usable knowledge will advance the membrane protein proteomics significantly. Nanoxis’ aspiration is to advance the membrane protein proteomics field by providing new innovative solutions.

Footnotes:
[1] Membrane Technology , volume 2008, Issue 3 , March 2008, p 4.
[2] Overington, J.P. et al. (2006) How many drug targets are there? Nat. Rev. Drug Discov.5, pp 993–996.