A multi-chamber membrane separation electrophoresis system supporting bio-affinity screening and evaluation of potential bioactive compounds in complex Chinese medicine.

An integrated platform of screening multi-compounds and evaluating bio-affinity is critical to explain the molecular mechanism of complex herbal medicine on various diseases. Here we developed a micro- and multi-chamber membrane separation electrophoresis system (MCMSE) based on the concept of bio-affinity, chamber-electrophoresis and membrane separation. It can enable simultaneous, rapid and high-throughput screening of multi- potential bioactive components in <15 min at low voltage (<35 V), which maintains the dynamic and original structure of biomacromolecules without immobilization. Based on the bio-affinity interaction and efficient separation of target protein/active components complexes and free small molecules, MCMSE demonstrates the function to determinate binding constants (K) between proteins and active components by the known interaction systems, with the potential for broad-spectrum determination. MCMSE has been applied to find 7 potential bioactive compounds of α-glucosidase (α-Gluc) from Scutellaria baicalensis Georgi extract, showing satisfactory screening reproducibility. Among these, the moderate bio-affinity interactions of three compounds with α-Gluc (isoschaftoside, baicalin, oroxylin A-7-O-glucuronide, wogonoside) were further verified by fluorescence quenching depending on the concentration of small molecules, with the K(s) =10 ∼ 10 M. The proposed bio-affinity screening and evaluation system has the advantages of non-immobilization targets, fast, universality to be a potential way to explore the interaction between single-target and multi bioactive components and elucidate synergistic mechanism of herbal medicine.