Proteins applications

Protein applications are extremely sensitive to solvent pH, salt concentration, and small molecular weight additives such as trifluoroacetic acid (TFA), which affect solute equilibria. These effects are known and depending on the specific application, proteins are often run under denaturing conditions, which offer vastly different retention conditions than nondenaturing conditions. 

Currently, protein microarrays can be divided into various types depending on the strategies to be chosen. For example, according to the array structure and shape, protein microarrays include 3D-surface structure [30, 31], nanowell [32], and plain chips [33-36], Meanwhile, considering the field of application, protein microarrays can be classified into five categories antibody array, antigen or reserve array, functional array, capture array, and solute array. Table 11.6 shows the differences among them. 

The minimal amount of applicable protein depends on the detection method. Mosdy detection by Coomassie staining is tenfold less sensitive than by silver staining, which drops down to 1 ng per band. 

Pharmacokinetics Poorly absorbed from the GI tract minimal absorption following topical application. Protein binding 9%-36%. Widely distributed. Partially metabolized in liver. Excreted primarily in urine. Removed by hemodialysis. Half-life 2.5 hr (increased in impaired renal function). 

Pharmacokinetics Well absorbed from theGl tract minimally absorbed after topical application. Protein binding less than 20%. Widely distributed crosses blood-brain barrier. Metabolized in the liver to active metabolite. Primarily excreted in urine partially eliminated in feces. Removed by hemodialysis. Half-life 8 hr (increased in alcoholic hepatic disease). 

In some technological and medical applications protein adsorption and/or cell adhesion is advantageous, but in others it is detrimental. In bioreactors it is stimulated to obtain favourable production conditions. In contrast, biofilm formation may cause contamination problems in water purification systems, in food processing equipment and on kitchen tools. Similarly, bacterial adhesion on synthetic materials used for e.g. artificial organs and prostheses, catheters, blood bags, etc., may cause severe infections. Furthermore, biofilms on heat exchangers, filters, separation membranes, and also on ship hulls oppose heat and mass transfer and increase frictional resistance. These consequences clearly result in decreased production rates and increased costs. 

Membrane contactor offers potential solution in a wide range of gas/liquid and liquid/liquid applications gas adsorption and stripping, liquid/liquid extraction, dense gas extraction, fermentation and enzymatic transformation, pharmaceutical applications, protein extraction, wastewater treatment, chiral separations, semiconductor manufacturing, carbonation of beverages, metal ion extraction, protein extraction, and VOCs removal from waste gas [55]. 

Pestka, S. Lin, L. Wu, W. Izotova, L., Introduction of protein kinase recognition sites into proteins a review of their preparation, advantages, and applications, Protein Expr. Purif. 1999, 17,203-214... 

A large variety of assays has been adapted to utilise protein microarrays. At its current state, the detection of immobilised antigens with antibodies is still the most common application. Protein and antibody arrays have been used for the selection and characterisation of novel antibodies from phage display libraries and for the identification of antigens (e.g., involved in autoimmune diseases). 

Even in more fundamental biomedical research the QCM is very versatile and broadly applicable. Proteins derived from native extracellular matrices may be deposited on the surface in order to study the interaction of cells with these protein coatings. A recent study by li and coworkers [11] has shown that the QCM provides similar readouts as the traditionally apphed cytolog-ical techniques. Due to its enormous time resolution even subtle differences in the kinetics of attachment and spreading become accessible. 

Most of the results obtained to date concern MIPs synthesised in organic media. They should now be transposed to aqueous systems which have a much broader field of application (protein recognition) and perspectives of development [132,133].This poses a certain number of problems since the interactions occurring in the two types of system are fundamentally different (Van der Waals interactions for organic systems and hydrophobic interactions and complexa-tion in aqueous media [134]). 

Dror, O., Benyamini, H., Nussinov, R., Wolfson, H.J. Multiple structural alignment by secondary structures Algorithm and applications. Protein Sci. 12(11), 2492-2507 (2003)... 

Staining the zones after focusing is somewhat of a headache. This is because practically all applicable protein dyes also stain the carrier ampholytes. Awdeh and co-workers have described a method of staining the proteins directly, even in presence of Ampholine chemicals. Otherwise it is necessary to fix the proteins and wash out the carrier amphol3rtes before staining can be done. Another way of removing the Ampholine before staining is by means of electrophoresis, as done by Dale and Latner (34). 

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