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O D RATNOFF

Publications and source records attributed to O D RATNOFF.

At least 73 records · Page 4Linked to original sources
PubMed1953

The inactivation of complement and its components by plasmin.

Human complement is inactivated by plasmin, the proteolytic enzyme of plasma or serum active at or near neutrality. The addition of streptokinase to human serum, which converts plasminogen to plasmin, also causes the inactivation of complement components C'2 and C'4 and varying amounts of C'1. C'3 is the most resistant to inactivation by plasmin. Chloroform-activated human plasmin and bovine plasmin also destroy these components of complement, but are less effective than the streptokinase-activated enzyme. The inactivation of complement by the addition of streptokinase to human serum is inhibited by high hydrogen ion concentrations, low temperature, and elevated ionic strength. The inactivation of the components of complement in various fractions of serum is influenced by the available plasminogen and the content of plasmin inhibitors in these fractions. Certain similarities are pointed out between the components of complement and the factors in the plasmin system and between the inactivation of the components of complement by antigen-antibody reactions, by specific agents, and by plasmin. The possible significance of these relationships in immune hemolysis and complement fixation, and the possible role of the plasmin system in the instability of complement and the development of anticomplementary properties in serum are discussed.

Animals↗
PubMed1953

The influence of calcium ions on the inactivation of human complement and its components by plasmin.

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.

Animals↗
PubMed1952

Studies on a proteolytic enzyme in human plasma. VIII. The effect of calcium and strontium ions on the activation of the plasma proteolytic enzyme.

Calcium ions accelerated the activation of the proteolytic enzyme of plasma from its precursor in the globulin fraction. Calcium did not appear to potentiate fibrinolysis by active bovine or human plasma proteolytic enzyme, nor did it accelerate the activation of the precursor of this enzyme by chloroform or by streptokinase. Experiments with partially purified plasma proteolytic enzyme suggested that the acceleratory effect of calcium was mediated indirectly. Since the concentration of calcium which was effective was comparable to that present in plasma, it is possible that the phenomena reported are of biological significance.

Animals↗