Chen Michelle, Corless Elliot I, Engelward Bevin P, Swager Timothy M
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
ACS Omega. 2024 Aug 22;9(35):37076-37085. doi: 10.1021/acsomega.4c03959. eCollection 2024 Sep 3.
When equal volumes of two immiscible liquids are mixed (e.g., a hydrocarbon and a fluorocarbon), Janus droplets can form in an aqueous solution. In a gravity-aligned Janus droplet, the boundary between the two phases is flat and thus optically transparent when viewed from above. When tipped due to interactions with an analyte (i.e., agglutination), the resulting change in refraction and reflection yields an optical signal that can be detected and quantified. This study reports the detection and quantitation of interleukin-6 (IL-6) using emulsions functionalized at the hydrocarbon:aqueous interface with engineered proteins that bind IL-6 at high affinity and specificity. Hyperthermophilic affinity proteins (rcSso7d) are derived from thermophiles, giving them excellent thermal stability. Two rcSso7d affinity protein variants were synthesized with a noncanonical azide-functionalized amino acid to enable click chemistry to novel polymeric anchors embedded in the hydrocarbon phase. The two binding proteins recognize different epitopes, enabling the detection of both monomeric and dimeric IL-6 via agglutination. It is noteworthy that the rsSso7d protein variants, in addition to having superior thermal stability and facile recombinant synthesis in , show superior performance when compared to commercial antibodies for IL-6.
当将等体积的两种互不相溶的液体混合（例如，一种碳氢化合物和一种氟碳化合物）时，在水溶液中会形成Janus液滴。在重力对齐的Janus液滴中，两相之间的边界是平的，因此从上方观察时是光学透明的。当由于与分析物相互作用（即凝集）而倾斜时，折射和反射的变化会产生一个可检测和定量的光学信号。本研究报告了使用在碳氢化合物：水界面功能化的乳液检测和定量白细胞介素-6（IL-6），该乳液带有能以高亲和力和特异性结合IL-6的工程蛋白。嗜热亲和蛋白（rcSso7d）源自嗜热菌，赋予它们出色的热稳定性。合成了两种带有非经典叠氮化物功能化氨基酸的rcSso7d亲和蛋白变体，以实现与嵌入碳氢化合物相中的新型聚合物锚定物的点击化学。这两种结合蛋白识别不同的表位，能够通过凝集检测单体和二聚体IL-6。值得注意的是，rsSso7d蛋白变体除了具有出色的热稳定性和在……中易于重组合成外，与用于IL-6的商业抗体相比，还表现出卓越的性能。
