L. Meunier et al., Optimized conditions to couple two water-soluble biomolecules through alkylamine thiolation and thioetherification, BIOCONJ CHE, 10(2), 1999, pp. 206-212
A simple method far introducing, in buffered saline, a reactive sulfhydryl
group on water-soluble molecules bearing an alkyl-amino group is described.
This method is based on the use of two water-soluble reagents: 2-iminothio
lane and 6,6'-dithiodinicotinic acid. The first one is open upon reaction w
ith an amino group, and the generated thiol group is immediately protected
by action of the second reagent. The optimal conditions were determined by
taking into account the stability and the reactivity of both reagents with
regards to pH and temperature. This method was validated through two applic
ations, the substitution of bovine serum albumin with a bromoacetyl peptide
and the substitution of an amino link at the 5' end of an oligonucleotide
by reaction with either a fluorescent tag, iodoacetamidofluorescein, or a b
romoacetyl peptide, upon reduction of the protected disulfide bridge with a
third water-soluble reagent, namely tris(2-carboxyethyl)phosphine.