甘露糖外切酶的细胞生物学定位研究

Possible subcellular localization of mannosidase

用不同试剂从西红柿种子提取甘露聚糖外切酶,结果表明甘露聚糖外切酶只能被含高盐的缓冲液(0.1mol/LHepes+500mmol/LNaCl,pH7.0)提取出来,单独的低盐缓冲液(0.1mol/LHepes,pH7.0)或用非盐洗涤剂代替高盐则不能提取该酶.通过基因枪将甘露聚糖外切酶和GFP融合蛋白转化洋葱表皮细胞,发现转化了甘露聚糖外切酶和GFP融合蛋白的洋葱表皮细胞壁上有荧光,表明甘露聚糖外切酶可能定位在细胞壁上.

β-mannosidase was extracted from tomato seeds with different buffers. The results show that the β-mannosidase activity is present in high salt buffer （0.1 mol/L Hepes ＋ 500 mmol/L NaCl, pH 7.0） , but not in low salt buffer. Non-ionic detergents can not replace the effect of high salt. By introducing the β-mannosidase-GFP fusion protein construct into onion epidermal cells via gene gun bombardment, fluorescence can he observed in the β- mannosidase-GFP transformed onion cells. This indicat that β-mannosidase might be localized in the cell wall.