Data/hora: 07/06/2024 02:46:07

Biblioteca(s): 	Embrapa Unidades Centrais.	
Data corrente: 	08/06/2004	
Data da última atualização: 	27/08/2018	
Autoria: 	SILVA, M. C. M. da; MELLO, L. V.; COUTINHO, M. V.; RIGDEN, D. J.; NESHICH, G.; CHRISPEELS, M. J.; SA, M. F. G. de.	
Afiliação: 	MARIA CRISTINA MATTAR DA SILVA, Cenargen; Luciane Vieira Mello, CENARGEN; MARISE VENTURA COUTINHO, Cenargen; Daniel John Rigden, CENARGEN; Goran Neshich, CNPTIA; Maarten John Chrispeels, Division of Biology, University of California San Diego; MARIA FATIMA GROSSI DE SA, Cenargen.	
Título: 	Mutants of common bean alpha-amylase inhibitor-2 as an approach to investigate binding specificity to alpha-amylases.	
Ano de publicação: 	2004	
Fonte/Imprenta: 	Pesquisa Agropecuária Brasileira, Brasília, DF, v. 39, n. 3, p. 201-208, mar. 2004	
Idioma: 	Inglês	
Notas: 	Titulo em português: Mutantes do inibidor-2 de alfa-amilase do feijão-comum para investigação da especificidade de ligação a alfa-amilases.	
Conteúdo: 	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.	
Palavras-Chave: 	a-amylase inhibitors; especificidade de interação; inhibitor specificity; inibidores de a-amilases; modelagem molecular; mutagênese sítio-dirigida; site directed mutagenesis; structural modeling.	
Thesagro: 	Phaseolus Vulgaris.	
Categoria do assunto: 	--	
URL: 	http://ainfo.cnptia.embrapa.br/digital/bitstream/AI-SEDE/26490/1/v39n03a01.pdf	
Registro original: 	Embrapa Unidades Centrais (AI-SEDE)	
Exemplares: 	AI-SEDE - (26490-1) - UPE - AP - PP - 630.72081 - P474 -  - DIS