Probing Protease-Mediated Decrease of Albumin-Catalyzed Kemp Elimination: Potential Application as Biosensors

Proteases function as “molecular scissors” to govern signaling pathways by modulating the levels of specific proteins. Herein, we report the ability of three different serine proteases – trypsin (Tr), chymotrypsin (ChT), and Proteinase K (PrK) in decreasing serum albumin-catalyzed Kemp elimination (KE) reaction in simple aqueous buffered media and complex body fluids, namely – urine and blood serum. We find with increasing albumin cleavage rate by proteases, the KE reactivity decreases and the order of KE reaction decreasing trend is: PrK > Tr > ChT. We demonstrate the utilization of this method in sensing albumin and trypsin in urine sample, important for diagnosing Kidney function and pancreatitis. Additionally, we report the albumin-catalyzed KE reactivity in complex environments like blood serum. In this case, the presence of additional Gamma globulin (GGB) shows a lesser effect in ChT-mediated decrease of albumin-catalyzed KE-reactivity, resulting a significant decrease in KE reactivity ratio of Tr/ChT and PrK/ChT. Understanding protease-specific functional alteration in a multiprotein environment can be utilized as an important tool not only for pathological purpose, but also in the designing of synthetic biochemical networks in complex biological media.