212 CHEMIfiTRY OF THE IMMUNITY REACTIONS 



tion. Acids stronger than COo and of the higher saturated or un- 

 saturated fatty acid series, inactivate complement in strengths greater 

 than n/^f,, and alkalies are equally inhibitiveJ Ultraviolet rays 

 destroy complement.''^ Sherwood "'' has made a study of various sub- 

 stances that maj" be present in the blood in excessive amounts during 

 pathological conditions, such as CO,, lactic acid, acetone, etc., and finds 

 that they interfere seriously with the action of complement, wliich 

 suggests that they may favor infection or interfere with recovery 

 from infection. 



Presumably the complement is a protein, for it has antigenic prop- 

 erties, so that immunization with sera containing either complement 

 or complementoid causes anticomplement activity in the blood of the 

 immune animal. Also, it is destroyed b^^ tiypsin free from lipase,^ 

 and, like other colloids, is readily adsorbed by surfaces; like enzymes, 

 complement is destroyed by shaking,'' and gradually disappears on 

 standing. There are some striking resemblances between the be- 

 havior of complement and of certain compounds of protein with soaps 

 and lipoids, as pointed out especially by Noguehi, but that these are 

 identical with true complement is doubtful. (See Hemolysis.) Its 

 colloid nature is attested by the large loss when complement is filtered 

 through Berkefeld filters.^" A careful review of the evidence has led 

 Liefmami " to the conclusion that the reaction of complement to sen- 

 sitized corpuscles is more like that of ferment to substrate than of 

 antigen to antibody. 



According to the Ehrlich theory, complement, like toxins and en- 

 zymes, possesses at least two groups : one, the haptophore, with which 

 it unites with the amboceptor; the other, the toxophore (or zymo- 

 phore, because of its enzyme-like action), which attacks the bacterial 

 protoplasm. It may degenerate and lose its toxophore group while 

 retaining the power to combine by means of its haptophore group, 

 thus forming a complementoid. Complement and amboceptor exist 

 side by side in the serum, not uniting with one another until the 

 amboceptor has become attached to the bacterial protoplasm. 



It is generally stated that if serum containing complement be so 

 treated as to separate the globulins from the albumin, it is found 

 that the complement has been divided into two parts, one present 

 in each of the protein fractions. The globulin fraction of the com- 

 plement will unite to amboceptor which is fixed to cells, and hence 

 is called the mid-piece of the complement, for it will unite also with 



TNofruchi, Biochem. Zeit., 1907 (6), 172. 

 TaCourmont et nl.. C. R. Soc. Biol., 1913 (74), 1152. 

 7b Jour. Infect, llis., 1917 (20), 18,5. 



8 Michaelis and Skwirsky, Zeit. Immunitiit., 1910 (7), 497. 



1) Nu<,riichi and Bronfonlircniior, Jour. K\-i>. Med., 19H) (1.'}), 229; Rilz, Zeit. 

 Immunitiit., 1912 (15), 145. 



10 See Sclimidt, Arch. f. Hy}j., 1912 (76), 284; Jour. llviJ:., 1914 (14), 4.37. 



11 Zeit. Immunitiit., 1913 (10), 503. 



