Improvement in the remaining activity of freeze-dried xanthine oxidase with the addition of a disaccharide–polymer mixture

Abstract

a b s t r a c tIn order to improve the remaining activity of a practically important freeze-dried enzyme, xanthine oxidase (XOD), the effects of disaccharide (sucrose and trehalose), polymer (bovine serum albumin: BSA and dextran) and a mixture of them on the loss of XOD activity during freeze-drying and subsequent storage were investigated. All samples were amorphous solids and their glass transition temperatures (T g ) were evaluated by using differential scanning calorimetry. Although dextran showed no stabilizing effect on the freeze-dried XOD, the others protected XOD from the activity loss during freeze-drying to a certain extent. It was found that the mixture of disaccharide (sucrose or trehalose) and BSA improved the XOD activity synergistically. The XOD activity of the samples decreased gradually during storage at a temperature range of between 25 and 60°C. Samples stored at temperatures below the T g showed a lower loss of XOD activity than those stored at just the T g .

Stabilization of freeze-dried Lactobacillus paracasei subsp. paracasei JCM 8130T with the addition of disaccharides, polymers, and their mixtures

“…[15][16][17][18][19][20][21] In addition, there are reports that a combination of disaccharides and polymers shows synergistic stabilizing effects on dehydrated proteins. 22,23) Since polymers have a high glass transition temperature (T g ), greater glass transition effect is expected than for disaccharides. In contrast, water substitution effect of polymers is less than saccharides because of the molecular stearic hindrance of polymers.…”

Stabilizing effects of sucrose–polymer formulations on the activities of freeze-dried enzyme mixtures of alkaline phosphatase, nucleoside phosphorylase and xanthine oxidase

“…For instance, two enzyme mixtures, NP-XOD and ALP-NP-XOD, are necessary in testing paper used to evaluate the freshness of fish, based on the change in the relative contents of nucleotides (e.g., inosine 5 0 monophosphate [IMP]) and nucleosides (e.g., inosine and hypoxanthine) in fish meat (Kaminashi, Nakaniwa, Kunimoto, & Miki, 2000;Srirangsan, Kawai, Hamada-Sato, Watanabe, & Suzuki, 2010). IMP !…”

“…XOD uric acid ALP is used to convert IMP to inosine. Likewise, inosine is converted to hypoxanthine by NP, and subsequently, XOD oxidizes hypoxanthine to xanthine and uric acid (Kalckar, 1947;Srirangsan et al, 2010). ALP, NP and XOD are, however, thermally unstable and become almost completely inactive during freeze-drying and subsequent storage.…”

“…Many efforts have been devoted to improving the stability of freeze-dried enzymes using additives (Allison, Chang, Randolph, & Carpenter, 1999;Anchordoquy & Carpenter, 1996;Anchordoquy et al, 2001;Izutsu, Yoshioka, & Kojima, 1995;Izutsu, Yoshioka, & Takeda, 1991;Kawai & Suzuki, 2007;Prestrelski et al, 1993;Schebor, Buera, & Chirife, 1996;Schebor, Burin, Buera, Aguilera, & Chirife, 1997;Srirangsan et al, 2010). Among the additives, sugar and polymer are usually effective (Allison et al, 1999;Anchordoquy et al, 2001;Chang, Beauvais, Dong, & Carpenter, 1996;Kreilgaard, Frokjaer, Flink, Randolph, & Carpenter, 1998;Prestrelski et al, 1993;Sampedro, Guerra, Pardo, & Uribe, 1998;Schebor et al, 1997;Wang, 2000).…”

“…In our previous study (Srirangsan et al, 2010), the effects of sugar, polymer and their mixtures on the remaining activity of freeze-dried XOD were investigated. The results indicated that sucrose and BSA were relatively good stabilizers.…”