Recommendation for the measurement of "alanine aminopeptidase" in urine.
نویسندگان
چکیده
A method is recommended for the measurement of the catalytic concentration of alanine aminopeptidase in the urine of man, rat, and dog, using L-alanine-4-nitroanilide as substrate. In currently used methods, substrate concentrations between 1.7 and 2.0 mmol/l are used. Kinetic experiments show, however, that the reaction is inhibited by substrate concentrations exceeding 0.8 (man), 0.3 (rat) and 0.5 mmol/l (dog); these concentrations lie in the range of the Km values. Assay conditions were therefore chosen to give the lowest possible Km. The Km value depends on the type of buffer, and it increases with pH and temperature. The recommended assay conditions are: triethanolamine buffer 70 mmol/l, pH 7.6; L-alanine-4-nitroanilide concentrations depending on the species; incubation temperature 25 degrees C.
منابع مشابه
Criteria for detection of heterozygous individuals with lactate dehydrogenase subunit deficiencies.
the measurement of “alanine aminopeptidase” in urine. J Clin Chem Clin Biochem 1988;26:635-44. 3. Jung K, ScholzD. An optimized assay of alanine aminopeptidase activity in urine. Clin Chem 1980;26:1251-4. 4. Flandrois C, Lahet C, Feldmann D, Gabastou JM, Gonnon A, Maire I. Urinary alanine aminopeptidase assay improved as result of multivariate response-surface analysis. Clin Chem 1988;34:954-7....
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ورودعنوان ژورنال:
- Journal of clinical chemistry and clinical biochemistry. Zeitschrift fur klinische Chemie und klinische Biochemie
دوره 26 10 شماره
صفحات -
تاریخ انتشار 1988