Development of a matrix metalloproteinase-2 (MMP-2) biosensing system by integrating β-lactamase-mediated chromogenic reaction with common electronic components
Matrix metalloproteinase-2 (MMP-2) plays an important role in extracellular matrix (ECM) degradation, which allows cancer cells to migrate out of the primary tumor to form metastases. Thus, it can serve as a biomarker for cancer diagnosis. Various methods have been developed to analyze MMP-2 activities, however, their wide applications for disease diagnosis have been hampered because high-end analytical equipment and labor-intensive processes are required. In this study, we developed an MMP-2 biosensing system by integrating an engineered autoinhibited β-lactamase-mediated chromogenic reaction into common electronic components such as a laser diode, solar cell, and multimeter. The autoinhibited β-lactamase was immobilized on a polymeric biosensing channel by a polydopamine coating and self-assembled monolayer methods. In the presence of MMP-2, the autoinhibited β-lactamase was turned to an active form which can hydrolyze CENTA, a chromogenic substrate of β-lactamase. As a result, the substrate color was changed from pale yellow (λmax = 340 nm) to dark yellow (λmax = 405 nm). By reading the interfered laser-light intensity, we were able to analyze MMP-2 activities precisely both with the samples prepared in a buffer solution and also those in urine. These results suggested that the developed system can be used for the quantitative analysis of enzyme activity related to cancer diagnosis.
