Evaluation of kinetic enzyme parameters by use of a small computer interfaced "Fast Analyzer"--an addition to automated clinical enzymology.

Abstract

The evaluation of steady-state enzyme kinetic pa-rameters such as Km, Vmax, and K1 is useful in clin-ical enzymology, particularly where they can be used for the detection of enzyme variants and to assess the type of isoenzymes and the extent of their abnor-mal activity. The multiple-cuvet parallel-analysis fea-ture of the Fast Analyzer permits one to evaluate one or more enzymic parameters in a single rotor. Both on-line measurement of initial reaction veloci-ties and rapid off-line reduction of statistical data can be obtained by using the small-computer inter-faced Fast Analyzer. Estimates of error in determin-ing these parameters are also obtained, for use in comparing results in future analyses. We discuss the programming approach for adapting both simple and more complex statistical nonlinear regression data-fitting routines to the Fast Analyzer’s computer. We illustrate how the analyzer may be used to determine simple kinetic parameters for placental alkaline phosphatase and glucose-6-phosphate dehyd roge-nase and for the more complex “stripping out ” of Km’S and Vmax’S for a heterogenous mixture of placental and intestinal alkaline phosphatase. Additional Keyphrases: alkaline phosphatase #{149}glu-cose-6-phosphate dehydrogenase #{149} isoenzymes