The role of N-acetyl-methioninate as a new stabilizer for albumin products

Sodium octanoate (Oct) and N-acetyl-L-tryptophanate (N-AcTrp) are widely used as stabilizers during the pasteurization of albumin products. However, N-AcTrp has a possible side effect of intracerebral disease. To provide safe and risk-free albumin products, we validated N-acetylmethioninate (N-AcMet) as a new stabilizer for albumin products. The effect of N-AcMet on oxidation was examined using 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) as an oxidizing agent. Carbonyl content in the presence of N-AcMet, as well as that in the presence of N-AcTrp after 24 h (Anraku et al., 2004), was significantly decreased. The effect of AAPH on the oxidative status of 34-Cys on human serum albumin was also studied by HPLC. It was found that N-AcMet as well as N-AcTrp, has a large protective effect on the sulfhydryl group after 1 h. Further, N-AcMet was found to be a superior radical scavenger to N-AcTrp using 1, 1'-diphenyl-2-picrylhydrazyl (DPPH) radicals. The thermal stabilizing role of N-AcMet manifested as an increase in denaturation temperature and calorimetric enthalpy, as determined by differential scanning calod metry (DSQ. In the present study, we suggest that use of N-AcMet in albumin preparation is safe and free of risk of side effects. (c) 2006 Elsevier B.V. All rights reserved.