Isolation of activating factors of serotonin N-acetyltransferase from rice peptides
| Autor: | Hiroshi Shimoda, Koji Kawakami, Seiji Tsuboi, Akiko Fujita, Chie Moritani, Tadashi Hatanaka, Kayoko Kawakami |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
endocrine system Sequence analysis Medicine (miscellaneous) Redox High-performance liquid chromatography Melatonin 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine medicine TX341-641 chemistry.chemical_classification Nutrition and Dietetics Chemistry Nutrition. Foods and food supply fungi Glutathione Serotonin N-acetyltransferase body regions 030104 developmental biology Enzyme Biochemistry Redox regulation Rice peptide Serotonin 030217 neurology & neurosurgery Intracellular Food Science medicine.drug |
| Zdroj: | Journal of Functional Foods, Vol 41, Iss, Pp 148-154 (2018) |
| ISSN: | 1756-4646 |
| Popis: | Serotonin N-acetyltransferase (AA-NAT), which converts serotonin to N-acetylserotonin, is a rate-limiting enzyme for melatonin synthesis. We previously reported that intracellular redox conditions regulate AA-NAT activity by switching an intramolecular disulfide bridge in a glutathione (GSH)-dependent manner; thus, increased GSH levels can activate AA-NAT. Here, we found that commercially available rice peptides increased intracellular GSH levels and attenuated H2O2-induced inactivation of AA-NAT activity in COS7 cells expressing AA-NAT constitutively. Purification of the peptides using a Sep-Pak C18 cartridge and three rounds of reversed-phase HPLC, followed by sequence analysis by mass spectrometry, led to the identification of three peptides. Two of these peptides (Pep2, VVTFGPSGLTTEVK; Pep3, YQQQFQQFLPEGQSQSQK) prevented inactivation of AA-NAT activity by H2O2. Only Pep3 increased intracellular GSH levels and prevented the decrease in the reduced/oxidised GSH ratio induced by H2O2. These results suggest that Pep3 activates AA-NAT by increasing intracellular GSH levels, which switches the intramolecular disulfide bond of AA-NAT. |
| Databáze: | OpenAIRE |
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