Standard measurements of free thiol on cell surfaces use the uptake of thiol-reactive substances which are incapable of traversing the membrane (reviewed in [l]). One problem is that dead cells are incapable of excluding such reagents, so that there is a risk of systematically high bias in the results, especially in delicate cells from patients. For example, one group showed a 3OOO% increase in...

Poly(ethylene glycol) (PEG)/polydimethylsiloxane (PDMS) hydrogels were synthesized by cross-linking norbornene end-functionalized polymers with a tetrafunctional thiol using thiol−norbornene chemistry. The swelling capacity and mechanical properties, including the Young’s modulus (E) and fracture toughness (Gc), of the hydrogels were characterized and quantified as a function of the volume frac...

Benzyl p-guanidinothiobenzoate hydrochloride was synthesized and demonstrated to be useful for active-site titration of bovine trypsin, bovine thrombin, human lung tryptase, bovine activated protein C, human Factor XIIa fragment and bovine Factor Xa beta. The titration is based on rapid formation of a stable acyl-enzyme with a stoichiometric release of benzyl thiol. Thiol production is measured...

Photoinitiated polymerization remains a robust method for fabrication of hydrogels, as these reactions allow facile spatial and temporal control of gelation and high compatibility for encapsulation of cells and biologics. The chain-growth reaction of macromolecular monomers, such as acrylated PEG and hyaluronan, is commonly used to form hydrogels, but there is growing interest in step-growth ph...

In order to obtain cell microarrays formed with human promyelocytic leukemia cells (HL-60), biotinylation of methacryloyl-functionalized HL-60 cells was performed via a thiol-ene reaction with thiol-terminated 4-arm poly(ethylene glycol) (PEG(4)10K-SH). Biotinylated HL-60 cells were selectively adhered onto an avidin-patterned surface with high viability.

A heterobifunctional reagent, N-succinimidyl 3-(2-pyridyldithio)propionate, was synthesized. Its N-hydroxysuccinimide ester group reacts with amino groups and the 2-pyridyl disulphide structure reacts with aliphatic thiols. A new thiolation procedure for proteins is based on this reagent. The procedure involves two steps. First, 2-pyridyl disulphide structures are introduced into the protein by...

We evaluated six precipitation methods for high-density lipoprotein cholesterol (HDL-chol) determination: the heparin/Mn2+ precipitation reagent method (Hep), two variants of the phosphotungstic acid/Mg2+ method (Tung-L and Tung-B), the dextran sulfate 50,000/Mg2+ method (Dex), the PEG 6000 method (PEG), and the PEG 6000/dextran sulfate 15,000 (PEG/Dex) method. The Tung-B and PEG/Dex precipitat...

The thiol reagent dithiothreitol inhibits the activity of a core GDP-fucose-N-acetylglucosaminide alpha-6-fucosyltransferase in plasma and blood-cell homogenates, while promoting the activity of alpha-2- and alpha-3-fucosyltransferases. The latter enzymes catalyse transfer of fucose on to terminal galactose and subterminal N-acetylglucosamine residues respectively. A thiol-blocking reagent N-et...

We report the use of phenolic functional groups lignosulfonate to impart antioxidant properties and cell binding domains gelatin enhance adhesion for poly(ethylene glycol) (PEG)-based scaffolds. Chemoselective thiol–ene chemistry was utilized form composites with thiolated (TLS) methacrylated fish (fGelMA). Antioxidant TLS were not altered after thiolation levels antioxidation comparable those ...

The accessibility of the cysteine residues of actin from rabbit muscles to the thiol-targeted reagent 7-dimethylamino-4-methyl-(N-maleimidyl)coumarin (DACM) was investigated. Under conditions where the actin is in the unpolymerized form (G-actin), the most reactive thiol group was Cys-257, suggesting that it was located on the surface of the actin molecule. The selective modification of Cys-374...