The determination of ϵ-amino groups in soluble and poorly soluble proteinaceous materials by a spectrophotometrie method using trinitrobenzenesulfonic acid
✍ Scribed by William A. Bubnis; Clyde M. Ofner III
- Publisher
- Elsevier Science
- Year
- 1992
- Tongue
- English
- Weight
- 449 KB
- Volume
- 207
- Category
- Article
- ISSN
- 0003-2697
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✦ Synopsis
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.