Reaction of Tris(2-carboxyethyl)phosphine (TCEP) with Maleimide and α-Haloacyl Groups: Anomalous Elution of TCEP by Gel Filtration

Labeling of Antibodies by in Situ Modification of Thiol Groups Generated from Selenol-Catalyzed Reduction of Native Disulfide Bonds

“…The gel-filtered antibody samples were assayed for protein concentration using their absorbance at 280 nm (⑀ 280 nm ϭ 1.4 mg Ϫ1 mL cm Ϫ1 ; MW 160 kDa) and for thiol concentration using Ellman's assay. A similar experiment with selenol/TCEP was not reliable because TCEP has an anomalous mobility in gelfiltration (23), resulting in an overlap of elutions of antibody and TCEP.…”

An efficient, chemically-defined semisynthetic lipid-adjuvanted nanoparticulate vaccine development system

“…Alternatively DMF was used, however lower product yields were observed. Use of TCEP to maintain reduced cysteine thiols is discouraged due to reactivity with maleimide groups 12,13 in the lipid adjuvant peptides. The reaction was performed as described.…”

“…Further, the products of this approach crosslink antigen and adjuvant into the same molecule, ensuring their co--delivery to cells of the immune system, an approach that in many cases significantly enhances the immune response towards attached antigens. 13 Maleimide conjugation was selected for this purpose as maleimides can be readily incorporated into our lipid adjuvants, are inexpensive to synthesize, 14 and enable simple, one--step conjugation reactions. Maleimides react specifically with thiols at neutral pH, generating a stable thioether linkage (Figure 1, A).…”

Aromatic Azido-selective Reduction via the Staudinger Reaction Using Tri-n-butylphosphonium Tetrafluoroborate with Triethylamine

“…As there are a few reports of the successful reduction of aromatic azides under mild conditions via the Staudinger reaction, 6 we refocused our attention on this approach. For example, Abe, Ito, and co-workers reported that azide 3 was efficiently reduced by treatment with an excess of tris(2-carboxyethyl)phosphine (TCEP), 7 which is a frequently used reductant in biological studies, to afford rhodamine derivative 4 exclusively, while treatment with triphenylphosphine provided the robust aza-ylide 5 ( Figure 1A). 6b The same group also developed a new azide-reducing reagent, o-(diphenylphosphino)benzamide (6), which was designed and synthesized to accelerate the hydrolysis of the aza-ylide 7 through neighboring group participation ( Figure 1B).…”