海藻酸凝胶性质对蛋白质扩散的影响

通过观察冷冻干燥海藻酸凝胶的断面扫描电镜(SEM)照片与卵清蛋白从海藻酸凝胶中的释放试验,分析了海藻酸凝胶性质对蛋白质在凝胶中扩散的影响。凝胶的SEM照片可见,海藻酸钙的冷冻干燥颗粒内为较大的圆孔,海藻酸锌凝胶内为较小的长孔,表明海藻酸锌高分子链在凝胶颗粒中的体积分率相对较大同时刚性较强;卵清蛋白从海藻酸凝胶颗粒中释放的试验结果表明,由于上述海藻酸锌凝胶的特性,导致海藻酸锌对卵清蛋白扩散阻滞作用相对较强;根据试验数据计算得卵清蛋白在海藻酸钙、海藻酸锌凝胶颗粒中的扩散系数分别为1.19×10-7、0.07×10-7cm2/s,利用阻滞模型计算得海藻酸锌高分子链在凝胶颗粒中体积分率约为海藻酸钙高分子链在凝胶颗粒中体积分率的1.7倍。

Effect of the characteristic of alginate gel on the release of protein from alginate beads

By the scanning electron microscopy (SEM) micrograph and the release experiments,the effect of the characteristic of alginate gel on the release of ovalbumin from alginate beads was investigated.The circinal cavities were found in calcium alginate beads and the cylinder holes were observed in zinc alginate beads from the SEM (micrograph),which indicated that the volume of fraction of zinc alginate polymer was relatively bigger and the zinc alginate polymer chain was more rigid than that of calcium alginate polymer chain.The result of release (experiments) of ovalbumin from alginate beads demonstrated that the diffusion of protein was slower in zinc alginate beads due to above characteristic of zinc alginate gels.The effective diffusion parameters of ovalbumin from calcium alginate beads and zinc alginate beads were 1.19×10~(-7), 0.07×10~(-7) cm~2/s respectively.The volume of fraction of zinc alginate polymer was 1.7 times that of calcium alginate polymer calculated from obstruction theory.