198 MECHANISM OF COMPLEMENT ACTION 



this substance is soluble in warm water, and hardly soluble in benzene, 

 while complement is an aqueous solution, and is not easily injured by 

 extraction with benzene. ^'^ Lysocithin also forms an irreversible comi- 

 pound with emulsified cholesterol, thus reminding one of the fact 

 that emulsions of cholesterol "fix" complement. Furthermore, lyso- 

 cithin is formed by the action of venom lipase on lecithin but is de- 

 stroyed by the further action of the same agent ; removal of the second 

 fatty acid leaves the lecithin complex inactive.^^ These two steps 

 might be compared with the process which results in spontaneous 

 deterioration of complement. 



With these facts in mind we may proceed to picture the nature of 

 the hemolysin system in complement as follows : 



>C(CH2)nCH:CH(CH2)„CH3 '^C(CH2)nC< 



R 



O 



^OH 



\c(CH2):nCH, \c(CH2)mCH3 



i 

 >C(CH2)„CH:CH(CH2)nCH3 ^C(CH2)nC< 





o o o« 



-\ 



R<^ (In fat phase) — > R<^ (In fat phase) 



OH ^^^^^ OH 



i \ 



O. Ov .0 



^ C (CH2) nCH : CH (CH2) nCHs ^ C (CH2) „c/^ 



O^ O^ ^^« 



R<^ (In water phase) — ^ R<f (In water phase) 



OH "^^' . OH 



R(0H)2 



27 Schmidt, P., Z. Chcm. hid. KolL, 1912, xi, 5. 



^^Delezenne, C, and Fourneau, E., Bull. Soc. Chim., 1914, series 4, xv, 421. 



