Maeda H, Molla A, Oda T, Katsuki T
J Biol Chem. 1987 Aug 15;262(23):10946-50.
Extracellular serratial protease (56,000 Da) is known to be cytotoxic. Fluorescein isothiocyanate-labeled protease was found to form a complex with human alpha 2-macroglobulin (alpha 2M), and this enzyme-inhibitor complex was purified. The protease was found to be internalized by fibroblasts in culture as a complex with alpha 2M, which resulted in cell destruction. Regeneration of enzyme activity was confirmed in cells after 2-3 h of incubation. Chicken egg-white ovomacroglobulin, a homolog of human alpha 2M, formed a complex with this enzyme similarly and more tightly but failed to exhibit protease activity, cytotoxicity, and internalization into cells.
已知细胞外的粘质沙雷氏菌蛋白酶（56,000道尔顿）具有细胞毒性。发现异硫氰酸荧光素标记的蛋白酶与人α2-巨球蛋白（α2M）形成复合物，并且该酶-抑制剂复合物得到了纯化。发现该蛋白酶作为与α2M的复合物被培养中的成纤维细胞内化，这导致细胞破坏。孵育2-3小时后，在细胞中证实了酶活性的恢复。人α2M的同源物鸡卵清卵巨球蛋白与该酶类似地且更紧密地形成复合物，但未表现出蛋白酶活性、细胞毒性以及进入细胞的内化作用。
