N-Acetyl-L-leucyl-L-leucyl-L-methional

N-Acetyl-L-leucyl-L-leucyl-L-methional is a Calpain II inhibitor with an IC₅₀ of 0.24 μM against porcine Calpain II. N-Acetyl-L-leucyl-L-leucyl-L-methional forms a stable tetrahedral adduct with the thiol group at the active site of Calpain II, thereby inhibiting proteolytic activity. N-Acetyl-L-leucyl-L-leucyl-L-methionally inhibits cathepsins in a non-selective manner. N-Acetyl-L-leucyl-L-leucyl-L-methional reduces SARS-CoV-2 infection levels in human coronary artery endothelial cells in vitro. N-Acetyl-L-leucyl-L-leucyl-L-methional can be used in research related to cataracts and coronavirus infections^[1][2][3]. In Vitro:N-Acetyl-L-leucyl-L-leucyl-L-methional inhibits purified porcine heart calpain II with an IC₅₀ value of 0.24 μM^[1].
N-Acetyl-L-leucyl-L-leucyl-L-methional (200 μM; pre-incubated for 12 h prior to treatment with Calcimycin (HY-N6687); detected after 5 d of culture) does not significantly reduce A23187-induced nuclear opacity in isolated lenses from 4.5-week-old Sprague-Dawley rats, and instead induces diffuse lens opacity^[1]
N-Acetyl-L-leucyl-L-leucyl-L-methional (70 μM; used in combination with 177 μM Calpain Inhibitor I; pre-treated for 30 min; co-incubated for 12-24 h) attenuates Prostaglandin E2 (HY-101952)-induced degradation of Ankyrin R in human red blood cells. It does not reduce PGE2-induced phosphatidylserine externalization at 24 h^[2].
N-Acetyl-L-leucyl-L-leucyl-L-methional (1 µM; 3 days post-infection) significantly reduces the level of SARS-CoV-2 spike protein in human coronary artery endothelial cells (HCAEC)^[3].