N. Kosower, E. Kosower
1987
Citations
5
Influential Citations
145
Citations
Quality indicators
Journal
Methods in enzymology
Abstract
Publisher Summary This chapter describes the use of three bromobimanes for fluorescent labeling of biological systems. The three bromobimanes, mBBr, bBBr, and qBBr, are commercially available. Bromobimanes are derived from a basic structure (two fused five-membered rings) with the requisite minimal size. In the course of preparing the bromo derivatives, it was found fortuitously that proteins were fluorescently labeled by bromobimanes. It was established that bromobimanes reacted preferentially with thiols and demonstrated the usefulness of such labeling for both small and large molecules in biological systems. Monobromobimane, mBBr, is the most frequently used in the series, not only as a labeling agent for thiols, but also for studies on the consequences of the alkylation of reactive thiols in biological systems. In a labeling reaction, involving multifunctional molecules like proteins, the first step involves displacement of the bromine of bBBr by a thiol, but the second bromine may react with a less reactive nucleophilic group if its local concentration is high, an expression of the neighboring group effect. This chapter discusses the labeling procedures including bromobimane solutions, reactions in solution, and reactions in cells and tissues.