Suc-Leu-Leu-Val-Tyr-AMC is a tetrapeptide compound that serves as a fluorogenic substrate for the 20S proteasome [1], chymotrypsin-like proteases [2], and calpains [3], with maximum excitation and emission wavelengths of 345 nm and 445 nm, respectively. Proteases such as calpains and 20S proteasome specifically recognize and cleave the "Leu-Leu-Val-Tyr" sequence, releasing the AMC fluorophore [4]，this makes it a valuable tool for studying calpain activity and proteasomal degradation.
References:
[1]. Stein RL, Melandri F, Dick L. Kinetic characterization of the chymotryptic activity of the 20S proteasome. Biochemistry. 1996 Apr 2;35(13):3899-908.
[2]. Gardner RC, Assinder SJ, Christie G, et al. Characterization of peptidyl boronic acid inhibitors of mammalian 20 S and 26 S proteasomes and their inhibition of proteasomes in cultured cells. Biochem J. 2000 Mar 1;346 Pt 2(Pt 2):447-54.
[3]. Debiasi RL, Squier MK, Pike B, et al. Reovirus-induced apoptosis is preceded by increased cellular calpain activity and is blocked by calpain inhibitors. J Virol. 1999 Jan;73(1):695-701. doi: 10.1128/JVI.73.1.695-701.1999.
[4]. Sasaki, T., T. Kikuchi, N. Yumoto, et al. 1984.Comparative specificity and kinetic studies on porcine calpain I and calpainII with naturally occurring peptides and synthetic fluorogenic substrates.J. Biol. Chem. 259:12489–12494.
Suc-Leu-Leu-Val-Tyr-AMC 是一种四肽化合物，是20S蛋白酶体[1]、胰凝乳蛋白酶样蛋白酶[2]和钙蛋白酶 [3]的荧光底物，其最大激发波长和发射波长分别为345 nm和445 nm。钙蛋白酶和20S蛋白酶体能够特异性识别并切割"Leu-Leu-Val-Tyr"序列，从而释放出AMC荧光基团[4]，这使其成为研究钙蛋白酶活性和蛋白酶体降解的宝贵工具。