Isolation and Purification of Meprin α from the blood Serum of COVID-19 Patient

Abstract

Meprins are zinc metalloproteases that are membrane-bound and secreted from these membranes. Many of these enzymes are secreted from the cell membranes and some of them are attached to the cell membrane and act both extracellularly and intracellularly. They have a role in tissue differentiation and remodeling and the processing of physiologically active peptides and cytokines in adult tissues. The Meprin α enzyme was isolated and purified from the blood serum of COVID-19 patients using a variety of biotechniques, such as sedimentation with 65 percent ammonium sulphate, dialysis, and ion exchange chromatography, where one highly active main peak is separated by the DEAE-cellulose ion exchange method. The number of purifications was 16 times. Then, using Sephadex G-150 for gel filtration, it was found that there was one peak with strong activity for the Meprin α, which had gone through 30 purification cycles with a 55 percent recovery rate of the enzyme. Furthermore, the estimated molecular weight of Meprin α extracted and partially purified from blood serum (140560 Dalton) of one peak was determined using gel filtration chromatography (Sephadex G-150). The results show that the optimal conditions for the activity of the isolated and partially purified enzyme are a potassium phosphate buffer at a pH of (8), a reaction time of (15 minutes), and a temperature of (40°C) using a concentration of (0.48 mmol/L) of tetramethyl benzidine (TMB) substrate, The maximum velocity (Vmax) of Meprin α was 136.9 U/ml with an enzyme concentration of 150 ng/ml and Michaelis-Menten constant (Km) values of 0.133 mmol/L.