Fluorescent protein problems

In protein separations, adsorption of protein molecules to the channel wall is always a problem. For instance, adsorption of green fluorescent protein (GFP) to the walls of plastic polycarbonate microchannels is problematic [597]. To avoid protein adsorption, the microchannels normally need to be treated with coatings, such as (acryloylaminopropyl)trimethylammonium chloride (BCQ), [806,809,812] or methacrylocyloxyethylphosphorylcholine (MPC) [1032]. In... 

To overcome the above-mentioned problems and limitations a novel nomenclature for fluorescent proteins and chromoproteins... 

This is a rather serious problem. Some proteins have a slight catalytic activity that can be utilized in an assay although they are not enzymes. Or perhaps the protein -will serve as a substrate for a reaction. If a protein has no enzyme activity, but the molecular weight and/or pi is known, it can be detected by gel electrophoresis by looking for protein concentration at the right spot on the gel. Some proteins actually fluoresce, like the GFP (green fluorescent protein) produced by jellyhsh. In these cases, the intensity of the fluorescence could serve as the basis for an assay. 

The diagnostics of protein complexes is an intricate problem if a molecule contains more than one absorption/fluorescent center (Permyakov, 1992). The problem becomes much more complex if, in addition, the protein specimen (ensemble of molecules) is a mixture of several chemically nonidentical types of molecules (subensembles) which cannot be separated, i.e. their partial concentrations are unknown. The second situation is typical for the special kind of proteins, namely, fluorescent proteins (FPs) (Piatkevich et al., 2010). The solutions of FPs are usually mixtures of several typ>es of molecules, which are chemically different and have their own set of photophysical properties (Verkhusha et al., 2004). In this case for unambiguous interpretation of experimental data it is necessary to make simultaneous measurements of a large number of parameters, i.e. to simultaneously apply (or, better, synthesize) several spectroscopic methods. 

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