Kyotorphin synthetase activity in rat adrenal glands and spinal cord.
Peptides
; 17(3): 407-11, 1996.
Article
em En
| MEDLINE
| ID: mdl-8735966
ABSTRACT
Kyotorphin, an endogenous [Met5]enkephalin-releasing antinociceptive dipeptide (L-Tyr-L-Arg), is formed by kyotorphin synthetase from its constituent amino acids, L-Tyr and L-Arg, in the brain in an ATP-Mg(2+)-dependent manner. To elucidate the physiological role of kyotorphin in organs other than the brain, we examined the activity of kyotorphin synthetase in the rat adrenal glands and spinal cord. By Sephacryl S-300 gel-filtration chromatography of the soluble extracts from both the organs, the enzyme activity forming immunoreactive kyotorphin from L-Tyr and L-Arg in the presence of ATP and MgCl2 was detected in the fractions with the molecular mass of 200-300 kDa, being drastically reduced by the omission of ATP and MgCl2 from the reaction medium. The Km values of the partially purified adrenal and spinal kyotorphin synthetase for L-Tyr, L-Arg, ATP, and MgCl2 were close to those of the brain enzyme. The activity of adrenal kyotorphin synthetase was inhibited by some L-Arg analogues. NG-nitro-L-arginine methyl ester, alpha-methyl-L-ornithine and D-Arg, but not by NG-nitro-L-arginine and N-iminoethyl-L-ornithine. In the crude soluble extracts from the adrenal glands and spinal cord, kyotorphin was formed by kyotorphin synthetase, and also by the enzymatic processing of the precursor proteins, in the presence of physiological concentrations of L-Tyr and L-Arg in addition to ATP and MgCl2. Thus, kyotorphin synthetase resembling that in the brain is present in the rat adrenal glands and spinal cord. The present findings may predict a functional role of the L-Arg-kyotorphin pathway in these organs.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Peptídeo Sintases
/
Medula Espinal
/
Glândulas Suprarrenais
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Peptides
Ano de publicação:
1996
Tipo de documento:
Article
País de afiliação:
Japão