Department of Downstream Processing, Institute of Pharmacy, Faculty of Sciences I, Martin Luther University Halle-Wittenberg, 06099 Halle (Saale), Germany.
Biomacromolecules. 2010 Apr 12;11(4):896-903. doi: 10.1021/bm901248d.
Sodium caseinate films were produced using microbial transglutaminase as a protein cross-linking biocatalyst. Basic parameters for the film production, such as buffer type and concentration, pH, temperature, plasticizer concentration and its influence on transglutaminase activity, mold material for film casting, specimen width, and cutting method, were investigated and compared with standardized methods (DIN EN ISO 527-3). Surprisingly, a previously described sodium phosphate buffer (50 mM, pH 8.0) resulted in crystals after drying the films for 48 h. To avoid this deteriorating effect, the buffer system was optimized and finally a Tris-HCl buffer (20 mM, pH 7.0) was chosen for the production of transparent, smooth films without crystallization. Incubation time and temperature during enzyme treatment had a considerable influence on the mechanical properties of the films.
采用微生物谷氨酰胺转氨酶作为蛋白质交联生物催化剂制备了酪朊酸钠薄膜。考察并比较了薄膜生产的基本参数，如缓冲液类型和浓度、pH 值、温度、增塑剂浓度及其对转谷氨酰胺酶活性的影响、薄膜浇铸用模具材料、试样宽度和切割方法等，与标准化方法（DIN EN ISO 527-3）进行了比较。令人惊讶的是，先前描述的磷酸钠缓冲液（50 mM，pH 8.0）在将薄膜干燥 48 小时后会导致晶体形成。为了避免这种恶化的影响，优化了缓冲液体系，最终选择 Tris-HCl 缓冲液（20 mM，pH 7.0）用于生产透明、光滑的薄膜，而不会结晶。酶处理过程中的孵育时间和温度对薄膜的机械性能有很大的影响。
