Data/hora: 30/05/2024 13:58:20

Biblioteca(s): | Embrapa Mandioca e Fruticultura.
Data corrente: | 12/06/1996
Data da última atualização: | 12/06/1996
Autoria: | ALI, Z. M.; ARMUGAM, S.; LAZAN, H.
Afiliação: | Faculty of Lief Sciences, Universiti Kebangsaan Malaysia, Bangi, 43600Selangro,Malaysia.
Título: | B-galactosidase and its significance in ripening mango fruit.
Ano de publicação: | 1995
Fonte/Imprenta: | Phytochemistry, v.38, n.5, p.1109-1114, 1995.
Idioma: | Inglês
Conteúdo: | The fruit extracts of ripening cv. Harumanis mango contained a number of glycosidases and glycanases. Among the glycosidases, B-D-galactosidase (EC 3.2.1.23) appeared to be the most significant. The enzyme activity increased in parallel with increase in tissue softness during ripening. Mango B-galactosidase was fractionated into three isoforms, viz.B-galactosidase I,II and III by a combination of chromatographic procedures on DEAE-Sepharase CL-6B, CM-Sepharose and sephacryl S-200 columns. Apparent Km values for the respective B-galactosidase isoforms for p-nitrophenyl B-D-galactoside were 3.7, 3.3 and 2.7 mM, and their V max values were 209, 1024 and 62 nkat mg-1 protein. Optimum activity occurred at ca pH 3.2 for b-galactosidase I and II, and pH 3.6 forB-galactosidase III. Mango B-galactosidase and its isoforms have galactanase activity, and the activity of the latter in the crude extracts generally increased during ripening. The close correlation between changes in B-galactosidase activity, tissue softness, and increased pectin solubility and degradation suggests that B-galactosidase might play an important role in cell wall pectin modification and softening of mango fruit during ripening.
Palavras-Chave: | B-galactosidase; Harvest; Maduro; Mango fruit; Pectin degradation; Softening.
Thesagro: | Anacardiaceae; Colheita; Manga; Mangifera Indica.
Thesaurus Nal: | ripening.
Categoria do assunto: | --
Registro original: | Embrapa Mandioca e Fruticultura (CNPMF)
Exemplares: | CNPMF - (3743-1) - ADC - AP - -- - 581.05 -  - 581.05 - DIS