Quick and simple method for increasing the reduced albumin fraction in human serum albumin preparations by using stronger neo‐minophagen C

Abstract

Serum albumin exists in both oxidized and reduced forms. Reduced albumin shows higher antioxidative effects; however, the percentage of reduced albumin is low in human serum albumin (HSA) preparation. Stronger neo-minophagen C (SNMC) containing cysteine, a nucleophilic amino acid, has the potential to control the redox state of albumin. The aim of this study was to develop a method for increasing the fraction of reduced albumin in HAS preparation using SNMC. Human serum albumin preparations were purchased from four different manufacturers. As a reducing agent, SNMC (50, 100, or 200 µL) was added to 62.5 mg of each HSA preparation, and the mixture was incubated at room temperature for 10-480 min. The percentages of reduced albumin were determined by high-performance liquid chromatography. The percentage of reduced albumin in the HSA preparation significantly increased 15 min after treatment with 200 µL of SNMC (manufacturer A; 27.7 ± 0.18% vs. 78.7 ± 0.36%, P < 0.01), and a dose-dependent relationship was observed between the increase in the percentage of reduced albumin and dose of SNMC. Similar results were obtained with the other three HSA preparations. The percentage of reduced albumin reached its peak at 15 min after mixing SNMC with an HSA preparation, and then gradually decreased with duration, irrespective of the dose of SNMC. We devised a method for increasing the reduced albumin fraction in an HSA preparation by using SNMC. We also determined the time-and dose-differences in the effect of SNMC on redox state of HSA.