Björk I, Larsson L J, Lindblom T, Raub E
Biochem J. 1984 Jan 1;217(1):303-8. doi: 10.1042/bj2170303.
The stoichiometry of the individual steps, i.e. polypeptide chain cleavage, hydrolysis of the putative thioester bond and conformational change, of the reaction between alpha 2-macroglobulin and trypsin or chymotrypsin was analysed. The chain cleavage was monitored by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, the thioester hydrolysis by both a spectroscopic and a fluorimetric technique and the conformational change by tryptophan fluorescence. A stoichiometry of close to 2:1 was obtained for all reactions. This finding indicates that the alpha 2-macroglobulin half-molecule is an independent functional unit of the inhibitor, within which co-operativity between the two subunits may occur.
分析了α2-巨球蛋白与胰蛋白酶或糜蛋白酶反应中各个步骤的化学计量关系，即多肽链裂解、假定硫酯键的水解和构象变化。通过十二烷基硫酸钠/聚丙烯酰胺凝胶电泳监测链裂解，通过光谱和荧光技术监测硫酯水解，通过色氨酸荧光监测构象变化。所有反应均获得接近2:1的化学计量关系。这一发现表明，α2-巨球蛋白半分子是抑制剂的一个独立功能单元，两个亚基之间可能存在协同作用。
