[Degradation of deamidated proteins by tissue proteinases]

The rate of native and deamidized serum albumin in vitro splitting by the brain, liver, kidney, testicle and spleen tissue proteinases was studied at pH 3.2, 4.8, 7.2 and 8.5. The deamidized preparation of serum albumin was obtained during its incubation under sterile conditions at 37 degrees C. The amount of amide groups in the process of protein incubation decreased by 19.4% mainly due to readily hydrolyzed asparagine groups. Desamidated serum albumin is splitted by tissue proteinases more intensively than native albumin. Intensity of the splitting depends on pH of the incubation medium and proteinase source. Specific proteolytic activity to desamidated serum albumin is shown to decrease in old rats as compared to young ones.