缓冲液条件对水霉细胞壁结合Ca^(2+)的影响

Effects of the Condition of Tris-maleate Buffer on the Binding of Ca^(2+) to Cell Wall of Saprolegnia ferax

用原子吸收光谱研究了pH值、Tris 马来酸缓冲液浓度对水霉 (Saprolegniaferax)顶端生长菌丝细胞壁与Ca2 + 结合的影响 .发现在 pH 3.5～ 6 .0范围内 ,细胞壁结合的Ca2 + 随 pH值升高而增加 ,pH >6 .0时 ,细胞壁结合的Ca2 + 呈下降趋势 .细胞壁结合的Ca2 + 随Tris 马来酸缓冲液浓度升高而增加 ,Tris浓度高于 9mmol/L时 ,细胞壁结合的Ca2 + 则减少 .细胞壁最多可结合Ca2 + 量>6 0 μmol/L .证明细胞壁Ca2 + 确实是水霉顶端生长赖以维持的胞外Ca2 + 库 .

It was measured by atomic absorption spectrometry that the amount of Ca 2+ bound to cell walls was strongly affected by pH of Tris maleate buffer, the concentration of Tris maleate buffer. Over the range pH 3.5 to 6.0, the amount of Ca 2+ bound to cell walls increased with the pH, but decresed as more alkaline pH value. The amount of Ca 2+ bound to cell walls increased with the concentration of Tris maleate buffer when it was below to 9 mmol/L, but decreased at denser Tris maleate buffer. The maximum amount of Ca 2+ bound to cell wall was more than 65 μmol/L. It was identified that the Ca 2+ in cell wall were the store out of cell that sustained the tip growth of Saprolegnia ferax