Purification and biochemica characterisation of endoplasmic reticulum á 1-2-mannosidase from Sporothrix schenckiil
Mem. Inst. Oswaldo Cruz
;
105(1): 79-85, Feb. 2010. ilus, tab
Artigo
em Inglês
| LILACS
| ID: lil-539299
ABSTRACT
Alpha 1,2-mannosidases from glycosyl hydrolase family 47 participate in N-glycan biosynthesis. In filamentous fungi and mammalian cells, á1,2-mannosidases are present in the endoplasmic reticulum (ER) and Golgi complex and are required to generate complex N-glycans. However, lower eukaryotes such Saccharomyces cerevisiae contain only one á1,2-mannosidase in the lumen of the ER and synthesise high-mannose N-glycans. Little is known about the N-glycan structure and the enzyme machinery involved in the synthesis of these oligosaccharides in the dimorphic fungus Sporothrix schenckii. Here, a membrane-bound á-mannosidase from S. schenckii was solubilised using a high-temperature procedure and purified by conventional methods of protein isolation. Analytical zymograms revealed a polypeptide of 75 kDa to be responsible for enzyme activity and this purified protein was recognised by anti-á1,2-mannosidase antibodies. The enzyme hydrolysed Man9GlcNAc2 into Man8GlcNAc2 isomer B and was inhibited preferentially by 1-deoxymannojirimycin. This á1,2-mannosidase was localised in the ER, with the catalytic domain within the lumen of this compartment. These properties are consistent with an ER-localised á1,2-mannosidase of glycosyl hydrolase family 47. Our results also suggested that in contrast to other filamentous fungi, S. schenckii lacks Golgi á1,2-mannosidases and therefore, the processing of N-glycans by á1,2-mannosidases is similar to that present in lower eukaryotes.
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Assunto principal:
Sporothrix
/
Retículo Endoplasmático
/
Manosidases
Idioma:
Inglês
Revista:
Mem. Inst. Oswaldo Cruz
Assunto da revista:
Medicina Tropical
/
Parasitologia
Ano de publicação:
2010
Tipo de documento:
Artigo
/
Documento de projeto
País de afiliação:
México
/
Reino Unido
Instituição/País de afiliação:
Universidad de Guanajuato/MX
/
University of Aberdeen/GB
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