Miyata K, Nakamura M, Tomoda K
J Biochem. 1981 Apr;89(4):1231-7.
Serratia protease (TSP) [EC 3.4.24] was bound stoichiometrically to alpha 2 macroglobulin (alpha 2M), which was purified and crystallized from human plasma, but apo TSP was not bound. On formation of the TSP-alpha 2M complex the enzymatic activity of the bound TSP was affected with respect to substrates; Km values of the bound TSP were unchanged but Vmax values were reduced. alpha 2M was cleft at the mid-region of its subunits chains by TSP, which resulted in a conformational change of the alpha 2M molecule with TSP.
粘质沙雷氏菌蛋白酶（TSP）[EC 3.4.24]与α2巨球蛋白（α2M）按化学计量结合，α2M是从人血浆中纯化并结晶得到的，但脱辅基TSP不与之结合。TSP-α2M复合物形成时，结合的TSP的酶活性在底物方面受到影响；结合的TSP的Km值不变，但Vmax值降低。TSP在α2M亚基链的中部区域使其裂解，这导致α2M分子与TSP一起发生构象变化。
