High-resolution purification techniques

At present, the purification by chromatographic processes is the most powerful high-resolution bioseparation technique for many different products from the laboratory to the industrial scale. In this context, continuous simulated moving bed (SMB) systems are of increasing interest for the purification of pharmaceuticals or specialty chemicals (racemic mixtures, proteins, organic acids, etc.).This is particularly due to the typical advantages of SMB-systems, such as reduction of solvent consumption, increase in productivity and purity obtained as well as in investment costs in comparison to conventional batch elution chromatography [1]. 

The analytical approach applied in the PoweU et at. (2005) study represents a major advancement in our current study of the chemical structure of DOM. SDS-PAGE remains one of the few methods that wiU allow separation and purification of intact dissolved proteins proteomics, as applied by PoweU et at. (2005), is now routinely applied in the biochemical and biomedical fields but is rarely applied in the environmental sciences. A major advantage of these mass spectrometry based techniques (i.e., proteomics) is the relatively smaU quantity of material required for the analysis this opens up the possibility for analyzing peptides and proteins in total DOM with little or no pre-concentration. However, the presence of salts stUl needs to be minimized before effective mass spectra can be generated. A recent review by Mopper et at. (2007) highlights the application of high-resolution analytical techniques to study marine DOM composition, and we refer the reader to this review for a more comprehensive discussion of recent analytical advances. 

Structure determination of luciferin. Once a luciferin is obtained in a sufficient purity, the determination of luciferin structure should be attempted most of the important properties of luciferin are usually already obtained during the course of purification as a necessity. The structural study is considerably more straightforward than the extraction and purification, due to the availability of advanced methods, such as high-resolution mass spectrometry and various NMR techniques. If help or collaboration is needed in structure determination, the attractiveness of a luciferin will make it easy to find a good collaborator. However, the purified luciferin is usually an extremely precious material considering the effort spent in preparing it. To avoid accidental loss of the purified material, the chosen collaborator must have solid knowledge and experience in structure determination a criterion to be considered is that the person has successfully done the structure determination of at least one new natural product. 

After concentration, high-resolution chromatographic purification is usually undertaken. A variety of different chromatographic techniques are available, which separate proteins from each other on the basis of differences in various physiochemical characteristics (Table 3.18.) Detailed description of the theory and practice underlining these systems go far beyond the scope of this text, and are freely available in the scientific literature. 

Kumpalume P, Ghose S (2003), Chromatography the high-resolution technique for protein separation, In Hatti-Kaul R, Mattiasson B (Eds), Isolation and Purification of Proteins, Marcel Dekker, New York, pp. 29-56. 

Johansson, K.-E. (1989b) Protein recovery and blotting techniques, in Protein Purification - Principles, High-Resolution Methods and Applications (Janson, J.-C., L. Ryden, Eds.) VCH, Weinheim. 

Macfarlane, D.E. (1989) Two dimensional benzyldimethyl-n-hexadecylaimnonium chloride-sodium dodecyl sulfate preparative polyacrylamide gel electrophoresis a high capacity high resolution technique for the purification of proteins from complex mixtures. Anal. Biochem. 176,457-463. 

---