| abstract |
The invention relates to synthetic peptides which have amino acid sequences which correspond, in whole or in part, to the amino acid sequence of prothrombin and are antigenic, to the use thereof for the immunization of an animal and for the purification of specific antibodies, to antibodies against these peptides, and to the use of the antibodies for the determination of the fragments F 2 /F 1+2 . The antibodies hitherto used for the determination of the content of the fragments F 2 /F 1+2 have been induced by immunization with natural, highly purified prothrombin fragments F 2 /F 1+2 . The isolation of these prothrombin fragments is elaborate and costly, and the antibodies generated therewith show cross-reactions with intact prothrombin. Used for the immunization according to the invention are synthetic peptides which have amino acid sequences which correspond, in whole or in part, to the amino acid sequence of prothrombin and are antigenic. The resulting antibodies react specifically with the antigen used for the immunization; if the peptides contain the carboxyl-terminal amino acid sequence of the fragments F 2 /F 1+2 resulting after cleavage of the prothrombin molecule with factor Xa, then the antibodies generated react specifically with the fragments F 2 /F 1+2 but not with intact natural prothrombin, so that information can be gained about the degree of activation of prothrombin. |