Hovenberg H W, Davies J R, Herrmann A, Lindén C J, Carlstedt I
Department of Cell and Molecular Biology, Lund University, Sweden.
Glycoconj J. 1996 Oct;13(5):839-47. doi: 10.1007/BF00702348.
Airway mucus was collected from healthy and chronic bronchitic subjects. The chronic bronchitic sputum was separated into gel and sol phase by centrifugation and mucins were isolated using isopycnic density-gradient centrifugation in CsCl. The presence of the MUC5AC and MUC2 mucins was investigated with antisera raised against synthetic peptides with sequences from the respective apoproteins. The gel and sol phase of chronic bronchitic sputum as well as healthy respiratory secretions were shown to contain MUC5AC whereas the MUC2 mucin could not be detected. Rate-zonal centrifugation showed that the MUC5AC mucin was large, polydisperse in size and that reduction yielded subunits. Ion-exchange HPLC revealed the presence of two subunit populations in all secretions, the MUC5AC subunits always being the more acidic. MUC5AC is thus the first large, subunit-based, gel-forming respiratory mucin identified and this glycoprotein is biochemically distinct from at least one other population of large, gel-forming mucins also composed of subunits but lacking a genetic identity.
从健康人和慢性支气管炎患者中收集气道黏液。将慢性支气管炎患者的痰液通过离心分离为凝胶相和溶胶相，然后使用氯化铯等密度梯度离心法分离黏蛋白。用针对来自各自载脂蛋白序列的合成肽产生的抗血清研究MUC5AC和MUC2黏蛋白的存在情况。结果显示，慢性支气管炎患者痰液的凝胶相和溶胶相以及健康呼吸道分泌物中均含有MUC5AC，而未检测到MUC2黏蛋白。速率区带离心表明，MUC5AC黏蛋白体积大、大小多分散，还原后产生亚基。离子交换高效液相色谱显示，所有分泌物中均存在两个亚基群体，MUC5AC亚基总是酸性更强的。因此，MUC5AC是首个被鉴定出的基于亚基的大型凝胶形成性呼吸道黏蛋白，这种糖蛋白在生化性质上与至少另一群体的大型凝胶形成性黏蛋白不同，后者也由亚基组成，但缺乏基因一致性。
