High-performance liquid chromatographic determination of lipoamidase (lipoyl-X hydrolase) activity with a novel substrate, lipoyl-6-aminoquinoline
| Autor: | Kazuyuki Yoshikawa, Noriyuki Katsumata, Kou Hayakawa, Teiji Kimura, Toshiaki Tanaka, Kunio Yamauchi |
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| Rok vydání: | 1996 |
| Předmět: |
Swine
Kidney High-performance liquid chromatography Amidohydrolases Feces chemistry.chemical_compound Lipoamidase Hydrolase Animals Humans Chromatography High Pressure Liquid Fluorescent Dyes chemistry.chemical_classification Lipoyl-6-aminoquinoline Chromatography Milk Human Thioctic Acid biology Chemistry Brain Substrate (chemistry) General Chemistry Enzyme assay Intestines Lipoic acid Blood Enzyme Liver Biochemistry Aminoquinolines biology.protein 4-Aminobenzoic Acid |
| Zdroj: | Journal of Chromatography B: Biomedical Sciences and Applications. 679:41-47 |
| ISSN: | 0378-4347 |
| DOI: | 10.1016/0378-4347(95)00575-7 |
| Popis: | An HPLC lipoamidase (lipoyl-X hydrolase) assay method has been developed, which uses a novel fluorescent substrate, lipoyl-6-aminoquinoline (LAQ). LAQ is synthesized from lipoic acid and 6-aminoquinoline (AQ) through lipoyl chloride as an intermediate and is conveniently purified by washing with chloroform-methanol. Mechanistic studies on the time-course, the dependence on enzyme and substrate concentrations were performed by using LAQ and a model enzyme (milk lipoamidase). Moreover, this method was successfully applied to the direct determination of the lipoamidase (LAQ hydrolase) activity in samples of human liver, milk, stools and porcine serum. Using this novel synthetic lipoyl substrate, we demonstrated that LAQ hydrolase was present in some specific tissues; LAQ hydrolase was solely present in the grey matter and not in the white matter in the human cerebrum. Furthermore, LAQ hydrolase activity was shown to increase in human liver cancer. Thus, this enzyme assay method is expected to be applicable to the tissue distribution study and also to the basic research on human diseases such as cancer. |
| Databáze: | OpenAIRE |
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