Composite enzymatic test

A composite enzymatic test is a biochemical test for enzyme activity .

principle

The principle of the composite enzymatic test was developed by Otto Warburg . He had previously published the optical-enzymatic test for measuring the enzyme activities of NAD ⁺ -reducing enzymes . A photometric measurement of the change in color intensity during the reduction from NAD ⁺ to NADH was carried out. This test was designed to measure the activities of lactate dehydrogenase (LDH), malate dehydrogenase (MDH) and glutamate dehydrogenase(GLDH) is used. The composite enzymatic test, on the other hand, consists of measuring an enzyme activity for which no colored substrate is available. This extension of the method is achieved by combining the reaction of the enzyme to be determined ( indicator reaction) with another enzymatic reaction ( measuring reaction ) for which there is a measuring reaction with a change in color intensity. The products of the first reaction must partly agree with the substrates of the second reaction. This indirectly determines the enzyme activity and quantifies it in comparison to a standard series . Examples of composite enzymatic tests are the GOD-HRP test and the GPT-LDH test . When developing a composite enzymatic test, the optimal concentrations are determined and used for the components that are not to be measured.

Individual evidence

1. ↑ O. Warburg, W. Christian, A. Griese: Hydrogen transferring co-ferment, its composition and mode of action (1935). In: Biochem. Z. Volume 282, p. 157.
2. ↑ O. Balcke: The theoretical basics of the optical test according to O. Warburg. In: Pure and Applied Chemistry . 3, 1961, doi : 10.1351 / pac196103030465 .
3. ↑ Konrad Lang, Emil Lehnartz: Handbook of the physiological and pathological-chemical analysis (1964), 10th edition, Volume 6 Part A, Reprint Springer-Verlag (2013), ISBN 978-3-662-11689-0 , doi: 10.1007 / 978-3-662-11689-0 . Pp. 298, 308.