Biochemical and antigenic characterization of a new dipeptidyl-peptidase isolated from Aspergillus fumigatus.
J Biol Chem
; 272(10): 6238-44, 1997 Mar 07.
Article
em En
| MEDLINE
| ID: mdl-9045640
ABSTRACT
A novel dipeptidyl-peptidase (DPP V) was purified from the culture medium of Aspergillus fumigatus. This is the first report of a secreted dipeptidyl-peptidase. The enzyme had a molecular mass of 88 kDa and contained approximately 9 kDa of N-linked carbohydrate. The expression and secretion of dipeptidyl-peptidase varied with the growth conditions; maximal intra- and extracellular levels were detected when the culture medium contained only proteins or protein hydrolysates in the absence of sugars. The gene of DPP V was cloned and showed significant sequence homology to other eukaryotic dipeptidyl-peptidase genes. Unlike the other dipeptidyl-peptidases, which are all intracellular, DPP V contained a signal peptide. Like the genes of other dipeptidyl-peptidases, that of DPP V displayed the consensus sequences of the catalytic site of the nonclassical serine proteases. The biochemical properties of native and recombinant DPP V obtained in Pichia pastoris were unique and were characterized by a substrate specificity limited to the hydrolysis of X-Ala, His-Ser, and Ser-Tyr dipeptides at a neutral pH optimum. In addition, we showed that DPP V is identical to one of the two major antigens used for the diagnosis of aspergillosis.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Aspergillus fumigatus
/
Dipeptidil Peptidases e Tripeptidil Peptidases
/
Antígenos de Fungos
Idioma:
En
Ano de publicação:
1997
Tipo de documento:
Article