Protein basic biochemistry

This section begins with a general discussion of the basic biochemistry of peptides and proteins followed by discus-... 

Proteins are described as natural robots, as they seem to know exactly what they have to do within a cell or outside a cell (Tanford and Reynolds 2004). Of course like many other molecules, the function of a protein is determined by its structure. As mentioned, proteins may function in many ways (see Table 1.1). Much of the basic biochemistry of protein was established before the coming of the science of proteomics (see Stryer 1982 and Bell and Bell 1988). This was made possible by developing methods to separate and purify proteins, as well as to determine their specific activity, amino acid composition and sequence, and 3D dimensional structure. Methods were also developed to characterize other physical and biochemical properties, including their regulation and artificial synthesis. 

Amino acids arising from protein hydrolysate This analysis is used often in food industry as well in basic biochemistry. It is important in determination of the structure of protein and in the assessment of the nutritional value of different proteins. Here the analysis of about 20 amino acids is sufficient. This type of analysis is relatively more difficult than that for a single amino acid. 

This experiment provides a nice example of the application of spectroscopy to biochemistry. After presenting the basic theory for the spectroscopic treatment of protein-ligand interactions, a procedure for characterizing the binding of methyl orange to bovine serum albumin is described. 

PVDF-based microporous filters are in use at wineries, dairies, and electrocoating plants, as well as in water purification, biochemistry, and medical devices. Recently developed nanoselective filtration using PVDF membranes is 10 times more effective than conventional ultrafiltration (UF) for removing vimses from protein products of human or animal cell fermentations (218). PVDF protein-sequencing membranes are suitable for electroblotting procedures in protein research, or for analyzing the phosphoamino content in proteins under acidic and basic conditions or in solvents (219). 

The fundamental role of blood in the maintenance of homeostasis and the ease with which blood can be obtained have meant that the study of its constituents has been of central importance in the development of biochemistry and clinical biochemistry. The basic properties of a number of plasma proteins, including the immunoglobulins (antibodies), are described in this chapter. Changes in the amounts of various plasma proteins and immunoglobulins occur in many diseases and can be monitored by electrophoresis or other suitable procedures. As indicated in an earlier chapter, alterations of the activities of certain enzymes found in plasma are of diagnostic use in a number of pathologic conditions. 

The quantitative estimation of proteins is one of the basic requirements in biochemistry. In reviewing the biochemical literature for methods of fast and sensitive determination of the amount of protein, the large variety of proteins becomes evident, since the amount of protocols for quantitative protein seems to be innumerable. 

Du Pont s medical diagnostics and pharmaceutical businesses are underpinned by substantial basic research in molecular biology and biochemistry. For example, Du Pont recently announced an improved, more reliable test for detection of antibodies to the virus that causes acquired immunodeficiency syndrome. In another program the protein interleukin-2 produced in Du Pont s laboratories by recombinant DNA methods is being used in some very promising cancer research. 

Because of its acidic character, DNA is stained by basic dyes. Long before the days of modem biochemistry, the name chromatin was given to the material in the nucleus that was colored by basic dyes. At the time of cell division, the chromatin is consolidated into distinct chromosomes which contain, in addition to 15% DNA, about 10% RNA and 75% protein. 

R Garrett and C Grisham, Biochemistry, 2nd ed (1999), Saunders (Orlando, FL), pp 141-142,154-156,405-412 Basic principles of electrophoresis P Grabar and C Williams, Btocbim. Biopbys. Acta 10, 193-194 (1953) Application of Immunoelectrophoresis to protein separation... 

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