Development of an electrochemical lectin-based biosensor using a novel Galectin-1-Maltose Binding Protein fusion molecule

The development of new analytical devices is totally dependent on the integration of various areas such as biotechnology, chemical biology and genetic engineering. Such devices are essential for linking and elucidating chemical and biochemical processes by improving accuracy, sensitivity, and operational simplicity with low cost.1 An extremely interesting strategy to promote integration between electrochemical techniques and genetic engineering is the employment of lectin-based biosensors for the detection and quantification of biomolecules. In this work, we described the production of a novel chimeric-lectin composed by Galectin-1 (Gal-1), a multifunctional β-galactoside-binding protein which is being constantly investigated because of its intriguing role in cancer2, and Maltose Binding Protein (MBP). Also, the electrochemical behavior of (MBP-Gal-1) was reported using Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS). The soluble and homogenous preparation of MBP-Gal-1 was obtained by affinity chromatography on amylose resin and analyzed by SDS-PAGE, MALDI-TOF/TOF, Western-blot, and Dynamic Light Scattering (DLS). The pure MBP-Gal-1 presented molecular mass of 57,83 kDa. For EIS analyses, MBP-Gal-1 was immobilized onto bared gold electrodes and glassy carbon modified with a redox polymer, obtained from oxidation of N-(3-pyrrol-1-ylpropyl)-4,4’-bipyridine (PPB), which interacts with the MBP domain.3 Preliminary data on EIS suggested that this system provided an oriented immobilization of MBP-Gal-1 chimeric protein onto PPB-modified surface. In addition, Gal-1 lectin activity was preserved and was confirmed through interaction with lactose. These results suggest that MBP-Gal-1 could be a promising lectin-based biosensor for electrochemical platform to evaluate the interactions between Gal-1 and different targets.