Atomic force microscopy of gastric mucin and chitosan mucoadhesive systems
Atomic force microscopy of gastric mucin and chitosan mucoadhesive systems
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DOI：
10.1042/0264-6021:3480557
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发表时间：
2000-06-15
影响因子：
4.1
通讯作者：
Harding, SE
中科院分区：
文献类型：
--
作者：
Deacon, MP;McGurk, S;Harding, SE
原子力显微镜已被用于探测，在分子水平上，纯化的猪胃粘蛋白（PGM）和粘膜粘附阳离子聚合物，壳聚糖（海固化210+）之间的相互作用，与低程度（约200）。11%）的乙酰化。产生的图像详细描述了PGM和壳聚糖在0.1M乙酸盐缓冲液（pH 4.5）中的结构，然后是两种结构在相同缓冲液中的复合物。PGM在0.1 M醋酸盐缓冲液中显示长的线性丝状结构，与早期的电子显微镜和扫描隧道显微镜研究一致。壳聚糖分子在相同的缓冲液中也采用线性构象，但具有较小的平均长度和直径。它们似乎采用了与早期流体动力学测量一致的刚性线圈构象。将PGM和壳聚糖混合在一起后形成的复合物显示出大的聚集体。在0.1M离子强度缓冲液中，它们的直径为0.7 μ m，与以前的电子显微镜研究一致。缓冲液的离子强度对复合物结构的影响也进行了研究，并与分子流体动力学数据一起，表明相互作用主要是静电性质。
Atomic force microscopy has been utilized to probe, at a molecular level, the interaction between purified pig gastric mucin (PGM) and a mucoadhesive cationic polymer, chitosan (sea cure 210 +), with a low degree (approx. 11 %) of acetylation. Images were produced detailing the structures of both PGM and chitosan in 0.1 M acetate buffer (pH 4.5), followed by the complex of the two structures in the same buffer. PGM in 0.1 M acetate buffer revealed long linear filamentous structures, consistent with earlier electron microscopy and scanning tunnelling micoscopy studies. The chitosan molecules also adopted a linear conformation in the same buffer, although with a smaller average length and diameter. They appeared to adopt a stiff-coil conformation consistent with earlier hydrodynamic measurements. The complexes formed after mixing PGM and chitosan together revealed large aggregates. In 0.1M ionic strength buffer they were of the order of 0.7 mu m in diameter, consistent with previous electron microscopy studies. The effect of ionic strength of the buffer on the structure of the complex was also studied and, together with molecular hydrodynamic data, demonstrates that the interaction is principally electrostatic in nature.