When protein is extracted from broken cells, proteases can be released, which need to be rapidly inhibited to keep protein from being degraded. In the process of protein extraction, protease inhibitors need to be added to prevent proteolysis. Protease inhibitor broadly refers to a substance that binds to some groups on the active center of protease molecules, so that the protease activity decreases or even disappears, but does not denature the enzyme protein. The sensitivity of various proteases to different protein is different, so it is necessary to adjust the concentration of various proteases. Because the solubility of protease inhibitor in liquid is extremely low, it should be paid special attention to that protease inhibitor should be fully mixed in the buffer to reduce the precipitation of protease inhibitor. Pepstantin A can inhibit acid proteases such as pepsin, angiotensin, collagenase, cathepsin D and chymosin.
