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

Abstract

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.