Chemical and Biological Studies of the Reactions of Complement Components C′2, C′3 and C′5

[摘要] During the past 6 years it has been learned that activated C′1 acts enzymatically on C′4 and C′2, cleaving the latter molecule and producing a complex, C′42a, which is a new enzyme possessing the capacity to cleave the C′3 molecule. One of the fragments of C′3 becomes fixed at or near the cell-bound C′42a to yield the complex C′42a3 which possesses the capacity to react with C′5. Another fragment, molecular weight ca. 10,000, is spasmogenic for guinea pig ileum. The C′42a3 complex cleaves C′5. One of the fragments becomes fixed to the cell-bound C′42a. Another fragment, molecular weight ca. 15,000, is spasmogenic for guinea pig ileum and chemotactic for rabbit polymorphonuclear leukocytes.At ionic strength 0.15, the cell-bound C′5 will dissociate from EAC′42a35 in active form and can be transferred to EAC′42a3. The dissociated C′5 is extremely unstable in the fluid phase.

[学科分类] 生物科学（综合）