Data/hora: 05/06/2024 14:38:37

Provedor de dados: 	56	
País: 	Brazil	
Título: 	Purification and partial characterization of Phaseolus vulgaris seed aminopeptidase	
Autores: 	Abdala,A.P.; Takeda,L.H.; Freitas Jr.,J.O.; Alves,K.B.	
Data: 	1999-12-01	
Ano: 	1999	
Palavras-chave: 	Phaseolus vulgaris aminopeptidase; Bean seed aminopeptidase; Leucyl aminopeptidase.	
Resumo: 	The aminopeptidase activity of Phaseolus vulgaris seeds was measured using L-Leu-p-nitroanilide and the L-aminoacyl-ß-naphthylamides of Leu, Ala, Arg and Met. A single peak of aminopeptidase activity on Leu-ß-naphthylamide was eluted at 750 µS after gradient elution chromatography on DEAE-cellulose of the supernatant of a crude seed extract. The effluent containing enzyme activity was applied to a Superdex 200 column and only one peak of aminopeptidase activity was obtained. SDS-polyacrylamide gel electrophoresis (10%) presented only one protein band with molecular mass of 31 kDa under reducing and nonreducing conditions. The aminopeptidase has an optimum pH of 7.0 for activity on all substrates tested and the highest Vmax/KM ratio for L-Leu-ß-naphthylamide. The enzyme activity was increased 40% by 0.15 M NaCl, inhibited 94% by 2.0 mM Zn2+, inhibited 91% by sodium p-hydroxymercuribenzoate and inhibited 45% by 0.7 mM o-phenanthroline and 30 µM EDTA. Mercaptoethanol (3.3 mM), dithioerythritol (1.7 mM), Ala, Arg, Leu and Met (70 µM), p-nitroaniline (0.25 mM) and ß-naphthylamine (0.53 mM) had no effect on enzyme activity when assayed with 0.56 mM of substrate. Bestatin (20 µM) inhibited 18% the enzyme activity. The aminopeptidase activity in the seeds decayed 50% after two months when stored at 4oC and room temperature. The enzyme is leucyl aminopeptidase metal- and thiol group-dependent.	
Tipo: 	Info:eu-repo/semantics/other	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999001200006	
Editor: 	Associação Brasileira de Divulgação Científica	
Relação: 	10.1590/S0100-879X1999001200006	
Formato: 	text/html	
Fonte: 	Brazilian Journal of Medical and Biological Research  v.32 n.12 1999	
Fonte: 	info:eu-repo/semantics/openAccess