Diagnostic enzymology

Plasma also contains numerous other enzymes that perform no known physiologic function in blood. These apparently nonfunctional plasma enzymes arise from the routine normal destruction of erythrocytes, leukocytes, and other cells. Tissue damage or necrosis resulting from injury or disease is generally accompanied by increases in the levels of several nonfunctional plasma enzymes. Table 7-2 lists several enzymes used in diagnostic enzymology. 

Scanning Electron Microscopy and X-Ray Microanalysis Principles of Electroanalytical Methods Potentiometry and Ion Selective Electrodes Polarography and Other Voltammetric Methods Radiochemical Methods Clinical Specimens Diagnostic Enzymology Quantitative Bioassay... 

W13. Wilkinson, J. H., An Introduction to Diagnostic Enzymology. Arnold, London, 1962. 

Enzymes are proteins with catalytic properties clinical enzymology is the application of the science of enzymes to the diagnosis and treatment of disease. The principles of clinical enzymology will be mtroduced and discussed in this chapter. Individual topics include basic principles, enzyme kinetics, analytical enzymology, and diagnostic enzymology. 

Kristensen SR, Horder M. Principles of diagnostic enzymology. In Enzyme Tests in Diagnosis. Moss DW, RosaUd SB, Eds. London Edward Arnold, 1996, pp, 7-24. 

Moss DW. Enzyme reference materials their place in diagnostic enzymology. Ann Biol Chn 1994 52 143-6. 

This reaction provides ATP for muscle contraction (Chapter 21). Skeletal muscle contains predominantly CK3, whereas heart muscle (myocardium) contains CK3 and CK2. Serum normally contains a small amount of CK3 derived predominantly from skeletal muscle. Detection of CK2 in serum (in an appropriate clinical setting) is strongly suggestive of myocardial damage. Since an abnormal isoenzyme level may occur with apparently normal total activity of the enzyme, determination of the isoenzyme concentration is essential in the diagnostic enzymology. 

These enzymes have been linked here because they have some common applications in diagnostic enzymology. Alanine aminopeptidase (AAP) and leucyl arylamidase (LAAP) hydrolyze the N-terminal amino acids and some amino amides the enzymes respectively hydrolyze leucyl- and alanyl-4-nitroanilide substrates. These enzymes occur in microsomes and are also membrane bound they have been used in studies of both hepatotoxicity and nephrotoxicity. They should not be confused with cytosolic leucine aminopeptidase (LAP) this enzyme is an aminopeptidase that hydrolyzes N-amino acid residues of proteins, in particular those with an N-terminal 1-leucine, where l-leucyl-(3-napthylamide is commonly used as substrate. Urinary alanine aminopeptidase is a useful marker of nephrotoxicity (Jung and Scholz 1980). 

Lindena, J., and I. Trautschold. 1986. Catalytic enzyme activity concentration in plasma of man, sheep, dog, cat, rabbit, guinea pig, rat and mouse. Approach to a quantitative diagnostic enzymology. Journal of Clinical Chemistry and Clinical Biochemistry 24 11-18. 

Further reading Wilkinson, J.H. (1976). The Principles and Practice of Diagnostic Enzymology, (London Edward Arnold)... 

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