LEPOW I H, PILLEMER L, RATNOFF O D
J Exp Med. 1953 Sep;98(3):277-89. doi: 10.1084/jem.98.3.277.
Ca(++) potentiates the inactivation of human complement by streptokinase-activated plasmin and chloroform-activated bovine plasmin. The optimum concentration of Ca(++) varies between 10(-2)M and 10(-3)M, decreasing with increasing concentrations of streptokinase. The susceptibility of the components of complement to inactivation by plasmin is different in the presence and absence of Ca(++). C'2 and C'4 are most readily inactivated by plasmin in the presence of Ca(++), while C'1 disappears first in the absence of Ca(++). A large part of this C'1 disappearance is due to spontaneous inactivation. Similarities are pointed out between the influence of Ca(++) on the inactivation of the components of complement by antigen-antibody systems and by plasmin.
钙离子可增强链激酶激活的纤溶酶和氯仿激活的牛纤溶酶对人补体的灭活作用。钙离子的最佳浓度在10⁻²M至10⁻³M之间,随链激酶浓度的增加而降低。在有和没有钙离子的情况下,补体各成分对纤溶酶灭活的敏感性不同。在有钙离子存在时,C'2和C'4最容易被纤溶酶灭活,而在没有钙离子时,C'1首先消失。C'1的这种消失很大一部分是由于自发灭活。文中指出了钙离子对抗抗原抗体系统和纤溶酶对补体成分灭活的影响之间的相似之处。