A novel endopeptidase from Xenopus that recognizes alpha-helical secondary structure.
Cell
; 66(3): 541-54, 1991 Aug 09.
Article
em En
| MEDLINE
| ID: mdl-1868549
ABSTRACT
The magainin peptides of Xenopus laevis are broad-spectrum antimicrobial agents. Upon discharge from the skin glands, these basic, amphipathic peptides are each further processed at a single Xaa-Lys bond into half-peptides by a cosecreted protease. We describe the characterization and purification to homogeneity of this endopeptidase from Xenopus skin. The enzyme is a metalloprotease 110 kd in size. Analyses of substrate specificity revealed that the endopeptidase recognizes peptides that share the ability to adopt an amphipathic, alpha-helical motif composed of at least 12 residues, with one face strongly hydrophobic. Cleavage occurs on the amino side of a specific lysine that must be precisely positioned relative to the hydrophobic face of the alpha helix. This enzyme, which we propose to call "magaininase," represents a novel class of endopeptidases that hydrolyzes peptides on the basis of specific secondary structure rather than primary amino acid sequence.
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Base de dados:
MEDLINE
Assunto principal:
Endopeptidases
/
Xenopus laevis
/
Peptídeos Catiônicos Antimicrobianos
/
Proteínas de Xenopus
Idioma:
En
Ano de publicação:
1991
Tipo de documento:
Article