[Immunochemical properties of cyanogen bromide fragments of human serum albumin (author's transl)].

Fragments A, B and C obtained by CNBr degradation of human serum albumin (HSA) were studied by specific quantitative precipitation with anti-HSA sera. A co-precipitation has been observed between fragments B and C as well as between C and A which follow each others in the albumin molecule. On the contrary, there was no co-precipitation between fragments B and A which correspond respectively to the N- and C-terminal part of the albumin molecule. Moreover, using inhibition of passive haemagglutination, it has been observed that fragment A does not inhibit anti-B antibodies and fragment B does not inhibit anti-A antibodies. These results indicate that there are common antigenic sites to fragments B and C as well as to C and A but not to B and A. This is in agreement with the data upon the structure of HSA showing that it is made of three domains in linear sequence.