作者:Hidenori Yamanaka、Kimihiro Yoshizako、Yoshikatsu Akiyama、Hiroyuki Sota、Yukio Hasegawa、Yasuro Shinohara、Akihiko Kikuchi、Teruo Okano
DOI:10.1021/ac0263768
日期:2003.4.1
We introduce a novel affinity chromatography mode in which affinity ligands are secured to the media surface via collapsible tethers. In traditional affinity chromatography, the immobilized ligands act passively, and their local concentration is static. In collapsibly tethered affinity chromatography, the ligand can move dynamically in response to external stimuli, a design that enables marked changes in both the local concentration of the ligand and its surrounding environment without exchange of solvent. Using the thermoresponsive polymer poly(N-isopropylacrylamide) (PIPAAm) as a scaffold for ligand and hapten attachment, we were able to achieve controlled mobility and microenvironment alteration of the affinity ligand Ricinus communis agglutinin (RCA120). The glycoprotein target, asialotransferrin, was loaded onto a column in which PIPAAm was partially substituted with both RCA120 and lactose. At 5 °C, the column retained the glycoprotein, but released most (95%) of the asialotransferrin upon warming to 30 °C. This temperature-induced elution was much greater than can be explained by temperature dependency of sugar recognition by RCA120. The simplest explanation is that upon thermally induced dehydration and collapse of the PIPAAm chains, coimmobilized RCA120 ligand and lactose hapten are brought into closer proximity to each other, enabling immobilized lactose to displace affinity-bound asislotransferrin from the immobilized RCA120 lectin.
我们介绍了一种新颖的亲和层析模式,其中亲和配体通过可折叠的连接链固定在介质表面。在传统的亲和层析中,固定的配体是被动的,其局部浓度是静态的。在可折叠连接的亲和层析中,配体可以动态响应外部刺激,这种设计使得配体的局部浓度及其周围环境发生显著变化,而不需要更换溶剂。利用热敏性聚合物聚(N-异丙基丙烯酰胺)(PIPAAm)作为配体和小分子配体连接的支架,我们能够实现蓖麻凝集素(RCA120)亲和配体的可控移动和微环境改变。将目标糖蛋白,即无唾液酸转铁蛋白,加载到部分被RCA120和乳糖取代的PIPAAm柱上。在5°C时,柱子保留了糖蛋白,但在升温至30°C时释放了大部分(95%)的无唾液酸转铁蛋白。这种温度诱导的洗脱效果远大于RCA120对糖识别的温度依赖性所能解释的。最简单的解释是,当PIPAAm链因热诱导脱水和塌陷时,与乳糖小分子配体一起固定的RCA120配体被带到彼此更接近的位置,使得固定化的乳糖能够取代与固定化的RCA120凝集素亲和结合的无唾液酸转铁蛋白。