Disulfide exchange reactions

These gold exchange reactions are prevented by prior alkylation of this protein thiol. Because of its lower affinity for gold when Cys-34 exists as a disulfide species, gold-to-sulfhydryl and gold-to-total albumin ratios are considered when analyzing data. Albumin with the Cys-34 blocked by alkylation is often used. 

Reglinski, J., Hoey, S. and Smith, W.E. (1988) Exchange reactions between disulfides and myocrisin an in vitro model for a mechanism in chrysotherapy. Inorganica Chimica Acta, 152, 261—264. 

Various new phosphonium salts were prepared in a one-pot reaction of carbon disulfide, phosphines, and 1 followed by an exchange reaction of the zirconated metal fragment with 2 equiv. of electrophiles (Scheme 8-23) [206],... 

Disulfide exchange reactions occur over a broad range of conditions—from acid to basic pH—and in a wide variety of buffer constituents. Most crosslinking reactions involving disulfide exchange are done under physiological conditions or those most appropriate to maintain stability of the protein or other molecule being modified. 

Preparation of Immunotoxin Conjugates via Disulfide Exchange Reactions... 

Simanek el al. investigated the structure dependence of the kinetics of thiol-disulfide exchange reactions.[44] In general, the rate of exchange decreased as the size of the dendrimers increased. Dendrimers with disulfides attached near the core undergo exchange more slowly than dendrimers with disulfides at the periphery. No evidence was found for intramolecular macrocyclization (cooperative) exchange. 

The very rapid exchange reaction between dimethyl sulfide and MeSSMe2 (43) is accompanied by a much slower, and irreversible, reaction (47) between the same reagents that involves nucleophilic attack of the sulfide on one of the sulfonium methyl groups and that leads to the formation of trimethylsulfonium ion and dimethyl disulfide (Kim and Caserio, 1974). Other sulfides (RSCH3) react similarly to give RS(CH3)2. When the sulfide is trideuteriomethyl... 

Traditional sample preparation conditions to form SDS-protein complexes prior to electrophoretic analysis included heat treatment at elevated temperatures (e.g., In the case of non-reduced rMAbs, this could lead to sample preparation artifacts in the form of thermally induced fragmentation attributed to disulfide reduction and exchange reactions. Moreover, it was reported that high pH (>9.0) also enhanced the... 

C. Paul, K. Kirschner and G. Haenisch, Anal. Biochem. 101, 442 (1980) determine the deadtime for a stopped-flow apparatus using a disulfide exchange reaction. 

Danieli, B. Giardini, A. Lesma, G. PassareUa, D. Peretto, B. Sacchetti, A. Silvani, A. Pratesi, G. Zunino, F. Thiocolchicine-podophyllotoxin conjugates Dynamic libraries based on disulfide exchange reaction. J. Org. Chem. 2006, 71, 2848-2853. 

Covalent polymers with reversible properties arising from dynamic covalent bonds such as disulfide exchange reaction [47 9], transesterification [50,51], transetherification [52], and boronate ester formation [53] were reported without respect to DCC. These studies should involve DCLs in... 

Fig. 10 Covalent immobilization of ssDNA by thiol/disulfide exchange reaction between disulfide-modified oligonucleotides and mercapto-modified substrates...

Interestingly, if the tribromo compound is treated with five equivalents of n-BuLi, then tetralithiation occurs, as was shown by the isolation of an a-butyl-2,4,5-trimethylthio derivative after reaction with excess dimethyl-disulfide [87JCS(P1)1453]. The a-butyl group in the product is derived from reaction of the a-benzyl carbanion with the n-butyl bromide produced by the initial bromine-lithium exchange reaction (Scheme 59). However,... 

These early studies clearly revealed the inherent problems of the chemistry for site-directed formation of unsymmetrical disulfides that has to avoid formation of homodimers. These can result from (i) slow rates of activation of the cysteine peptide, (ii) disproportionation of the activated cysteine species, (in) weak activation and thus slow thiolysis by the second cysteine component and thus its oxidation to the homodimer as well as thiol/ disulfide exchange reactions on the unsymmetrical disulfide present in the reaction media. The latter side reactions are partly controlled by operating in degassed argon-saturated buffers or in organic solvents and preferably under acidic conditions where thiol/disulfide exchange reactions on the nonactivated disulfides, i.e. on the target unsymmetrical cystine peptide occurs at slow rates. 

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