Protein degradation in red cells exposed to 2,2′‐azo‐bis(2‐amidinopropane) derived radicals

Extensive proteolysis is observed when red blood cells are exposed to free radicals produced in the thermolysis of 2,2′‐azo‐bis(2‐amidinopropane). It is evaluated that nearly one amino terminal group is produced by each free radical introduced into the system. These groups are considered to arise mainly from band 3 fragmentation due to the action of red cell proteinases. Protein fragmentation takes place prior to significant hemolysis or lipid peroxidation, as evaluated by thiobarbituric acid‐reactive substances measurements.