Bubnis W A, Ofner C M
Philadelphia College of Pharmacy and Science, Department of Pharmaceutics, Pennsylvania 19104.
Anal Biochem. 1992 Nov 15;207(1):129-33. doi: 10.1016/0003-2697(92)90513-7.
A procedure using 2,4,6-trinitrobenzenesulfonic acid (TNBS) for the determination of epsilon-amino groups in soluble and poorly soluble proteinaceous materials is presented. The major modification from previous procedures is an extended TNBS reaction time to allow a stoichiometric reaction with amino groups. In addition, autoclave hydrolysis is used to assure sample dissolution for spectrophotometric measurements. The assay accuracy was evaluated by determining epsilon-amino groups of insulin and bovine albumin. The determinations differed from literature values by < or = 3.3%. The epsilon-amino group content of Type B gelatin was found to be 33.0 mol/gelatin molecule of 1000 residues and is in agreement with similar source gelatins and collagen. The coefficient of variation for determinations on all three materials was < or = 5.3%. The assay should be applicable to a broad range of proteinaceous materials.
本文介绍了一种使用2,4,6-三硝基苯磺酸（TNBS）测定可溶性和难溶性蛋白质材料中ε-氨基的方法。与先前方法的主要改进之处在于延长了TNBS反应时间，以使其与氨基进行化学计量反应。此外，采用高压釜水解来确保样品溶解以便进行分光光度测量。通过测定胰岛素和牛血清白蛋白的ε-氨基来评估该测定方法的准确性。测定值与文献值的差异≤3.3%。发现B型明胶的ε-氨基含量为每1000个残基的明胶分子33.0摩尔，这与类似来源的明胶和胶原蛋白一致。对所有三种材料的测定变异系数≤5.3%。该测定方法应适用于广泛的蛋白质材料。
