Data/hora: 10/06/2024 01:30:06

Provedor de dados: 	86	
País: 	Brazil	
Título: 	Mutants of common bean alpha-amylase inhibitor-2 as an approach to investigate binding specificity to alpha-amylases	
Autores: 	Silva,Maria Cristina Mattar da; Mello,Luciane Vieira; Coutinho,Marise Ventura; Rigden,Daniel John; Neshich,Goran; Chrispeels,Maarten John; Grossi-de-Sá,Maria Fátima.	
Data: 	2004-03-01	
Ano: 	2004	
Palavras-chave: 	Phaseolus vulgaris; A-amylase inhibitors; Inhibitor specificity; Site directed mutagenesis; Structural modeling.	
Resumo: 	Despite the presence of a family of defense proteins, Phaseolus vulgaris can be attacked by bruchid insects resulting in serious damage to stored grains. The two distinct active forms of a-amylase inhibitors, a-AI1 and a-AI2, in P. vulgaris show different specificity toward a-amylases. Zabrotes subfasciatus a-amylase is inhibited by a-AI2 but not by a-AI1. In contrast, porcine a-amylase is inhibited by a-AI1 but not by a-AI2. The objective of this work was to understand the molecular basis of the specificity of two inhibitors in P. vulgaris (a-AI1 and a-AI2) in relation to a-amylases. Mutants of a-AI2 were made and expressed in tobacco plants. The results showed that all the a-AI2 mutant inhibitors lost their activity against the insect a-amylases but none exhibited activity toward the mammalian a-amylase. The replacement of His33 of a-AI2 with the a-AI1-like sequence Ser-Tyr-Asn abolished inhibition of Z. subfasciatus a-amylase. From structural modeling, the conclusion is that the size and complexity of the amylase-inhibitor interface explain why mutation of the N-terminal loop and resultant abolition of Z. subfasciatus a-amylase inhibition are not accompanied by gain of inhibitory activity against porcine a-amylase.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2004000300001	
Editor: 	Embrapa Secretaria de Pesquisa e Desenvolvimento

Pesquisa Agropecuária Brasileira	
Relação: 	10.1590/S0100-204X2004000300001	
Formato: 	text/html	
Fonte: 	Pesquisa Agropecuária Brasileira  v.39 n.3 2004	
Fonte: 	info:eu-repo/semantics/openAccess