Determination and Derivatization of Protein Thiols by n-Octyldithionitrobenzoic Acid

摘要: Abstract n -Octyl-5-dithio-2-nitrobenzoic acid (ODNB), the reaction product of -octane-1-thiol and Ellman′s reagent, can be isolated in crystalline form. Like ODNB used for titration SH groups proteins, but with considerable advantages: Due to absence one negative charge presence a lipophilic hydrocarbon chain, titrations protein thiols are significantly faster. Normally, endpoints reached after 5-30 min, while corresponding reagent may take 1-2 h. Another advantage is that it finds access thiol which normally remain undetected. With myosin S1, example, reacts group not reactive reagent. Although has detergent properties, this as consequence denaturation seems unlikely, because was below its critical micelle concentration all other S1 remained buried. The -octylthiol derivatives proteins formed by transient protection thiols, during purification procedures, or reversible blocking involved biochemical reactions.