Enkephalin-degrading activity in Xenopus laevis tadpoles and adults blood.
The enkephalin-degrading enzyme (alpha-aminoacyl-peptide hydrolase,EC 3.4.11.11) responsible for the rapid inactivation of enkephalins in human blood was purified and compared to the enkephalin-degrading system of Xenopus laevis tadpoles and adult blood. The specificity and the kinetic constants of the Xenopus enzyme(s) were determined after partial purification. Even if remarkable similarities between the Xenopus and the human enzyme exist, still they show differences in specificity towards peptides whose N-terminal is Phe. Amphibians are able to manufacture enkephalins and the present work shows that they are endowed with an enkephalin-degrading system comparable to the soluble one of human blood.
Coletti-Previero
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M
Centre de Recherche INSERM, 60 Rue de Navacelles, 34100 Montpellier, France.
Mattras
H
H
Previero
A
A
Pies
W
W
Zwilling
R
R
D000595:Amino Acid Sequence; D000626:Aminopeptidases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000818:Animals; D004745:Enkephalins / Q000378:metabolism*; D006801:Humans; D007814:Larva / Q000201:enzymology*; D010455:Peptides / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity; D014982:Xenopus laevis / Q000097:blood* / Q000254:growth & development
D004745:Enkephalins; D010455:Peptides; D000626:Aminopeptidases; C025579:enkephalin degrading enzyme