AMBOCEPTOR AND COMPLEMENT 213 



the end-piece of tlie complement contained in the albumin fraction, 

 and then cytolysis can take place. Without the intervention of the 

 globulin mid-piece the albumin end-piece cannot unite with the am- 

 boceptor, while in the absence of end-piece the amboceptor mid-piece 

 complex can cause no cytolysis. Both fractions of the complement 

 are destroyed by heat, but if the mid-piece is bound to the ambo- 

 ceptor it resists heating. The mid-piece corresponds to Ehrlich's 

 haptophore, the end-piece to the toxophore group, and this complex 

 structure is common to both bacteriolytic and hemolytic complement. 

 Bronfenbrenner and Noguehi,"-'' however, contend that the supposed 

 cleavage of complement is merely an inactivation by the agencies em- 

 ployed, all the complement being in the albumin fraction in a condi- 

 tion capable of reactivation, not only by globulin but by simple 

 amphoteric substances, a view which has not been generally accepted. 



In its effect of dissolving bacteria (and also other cells against 

 which animals may have been immunized) complement resemJjles the 

 enzymes, and by many it is looked upon as related to. them, but the 

 changes it produces do not resemble those produced by proteolytic en- 

 zj-mes in all details."'' In particular, complement seems to participate 

 in reactions according to the law of definite proportions, unlike the 

 enzymes.^- In certain immune reactions, colloids (lecithin, silicic 

 acid) ^^ can play the role of complement and immune body, but these 

 reactions are probably quite different from those of bacteriolysis by 

 immune serum. 



Amboceptors are formed, according to Wassermann, and Pfeift'er 

 and ]\Iarx, in the spleen and hemopoietic organs, since in immuniza- 

 tion i\\ey can be demonstrated in these organs before they appear in 

 the circulating blood. The stability of the amboceptors is very con- 

 siderable : serum prepared in 1895 by Pfeiffer against cholera vib- 

 rios was found to have lost almost none of its activity after eight 

 years in an ice-box (Friedberger). Heating twenty hours at 60° 

 scarcely injures them, but 70'^ for one hour destroys them almost 

 completely, and heating the serum to 100° destroj^s all the immune 

 bodies. They are quite resistant to putrefaction, and, like the anti- 

 toxins, do not dialyze. Strong salt solutions will prevent the union 

 of complement and amboceptor in vitro, and probably to greater or 

 less degree in the animal body, but the union of antigen and ambo- 

 ceptor is not prevented by salt.^* Alkalies may prevent the union 

 of amboceptor with the cells, or extract it from the cell to w^hich it 

 has united; and they may also inhibit the union of amboceptor and 



iia Jour. Exp. Med., 1912 (5), 598; good review of literature, 

 lib The curve of coiupleraent action resembles that of enzvnic action. (Tliiele 

 and Embleton. -Jour. Patli. and Bact... 191,5 (19), .372.) 



12 See Liebermann, Dent, nietl. \Yoch., 1906 (32), 249. 



13 Landsteiner and Jagic, Wien. klin. Woch., 1904 (17). 03: Miincli. med. 

 Woch., 1904 (.51), 1185. 



i4Angerer, Zeit. Immunitat., 1909 (4), 243. 



