Kinetics of acetyl CoA: Arylamine n‐acetyltransferase from human hepatocellular carcinoma
| Autor: | Chi F. Hung, Chin C. Yeh, Chin C. Ho, Yih S. Lai, Jing-Gung Chung, Yi H. Liu, Jau H. Lee |
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| Rok vydání: | 1999 |
| Předmět: | |
| Zdroj: | Toxicological & Environmental Chemistry. 71:197-210 |
| ISSN: | 1029-0486 0277-2248 |
| DOI: | 10.1080/02772249909358792 |
| Popis: | N‐acetyltransferase (NAT) activity and Michaelis‐Menten kinetic constants were determined in hepatocellular carcinoma and non‐cancerous liver tissues from thirty patients. The results derived from tissues showed that 5 rapid, 9 intermediate and 16 slow acetylators based on 2‐amino‐fluorene and p‐aminobenzoic acid as substrates. Overall, the normal liver NAT activity was higher than the cancerous liver NAT activity. The activities (mean ± SD) of NAT from normal and cancerous liver was 3.60 ± 0.98 and 2.18 ± 0.44 nmol/min/mg protein for the acetylation of aminofluorene, and 3.02 ±0.69 and 1.98 ±0.42 nmol/min/mg protein for the acetylation of p‐aminobenzoic acid. Compared to the enzymes from slow acetylators, the rapid acetylators exhibited mean apparent K m and V max values 2.4‐ and 2.6‐, 2.4‐ and 2.7‐fold greater for 2‐amino‐fluorene and /7‐aminobenzoic acid, respectively. In the hepatocellular carcinoma and normal liver tissues, 65% and 58%, 33% and 36% of NAT activities were inhibited under 2.0 mM of 5‐f... |
| Databáze: | OpenAIRE |
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