Determination of free amino groups in proteins by trinitrobenzenesulfonic acid.
- A. F. S. A. Habeeb
CiteWeb id: 19660000042
CiteWeb score: 2386
A sensitive method to determine the free amino groups in proteins is presented that makes use of the reagent 2,4,6-trinitrobenzenesulfonic acid. The relationship between absorbance and concentration (up to 1 mg/ml) was linear and the color was developed under more gentle conditions than with the ninhydrin method. It was found that sodium dodecyl sulfate was bound to some of the ϵ-amino groups of lysine in bovine serum albumin, ovalbumin, and human γ-globulin and rendered the involved amino groups unreactive toward TNBS. Partial reaction of 4 M potassium thiocyanate at 40°C for 2 hr with the free amino groups in bovine serum albumin, ovalbumin, human γ-globulin, and lactalysate was demonstrated by this method. The method was useful to study the reaction of the free amino groups of bovine serum albumin with formaldehyde.Links to full text of the publication: