The binding of thiol, thiolate, thioether, and disulfide sulfur donor ligands to ferric cytochrome P-450-CAM and myoglobin has been investigated by W-visible absorption, magnetic circular dichroism (MCD), and EPR spectroscopy. For ferric P-450, the binding of all sulfur donors is competitive with substrate binding. Addition of thiols to P-450 leads to interconvertible thiol or thiolate-bound sp...

Pyrazole and benzotriazole-containing thioethers, namely 1,5-bis(3,5-dimethylpyrazol-1-yl)-3-thiapentane, 1,8-bis(3,5-dimethylpyrazol-1-yl)-3,6-dithiaoctane and 1,3-bis(1,2,3-benzotriazol-1-yl)-2-thiapropane were prepared and fully characterized. Oxidation of the pyrazole-containing thioether by hydrogen peroxide proceeds selectively to provide a sulfoxide or sulfone, depending on the amount of...

Bifunctional tetrakis(methylthio)-1,4-benzenedicarboxylic acid and Pb2+ ions form a robust porous net featuring free-standing thioether groups that allow reversible uptake of HgCl2.

Z. Naturforsch. 56 b, 901-907 (2001); received June 5, 2001 Macrocyclic Ligands, Nitrogen, Sulfur The ability of the aromatic tetraaldehyde l,2-bis(4-rm-butyl-2,6-diformylphenylsulfanyl)ethane (1 ) to function as a precursor in the preparation of binucleating hexaamine-dithiolate lig­ ands has been investigated. Reductive amination of compound 1 with bis(aminoethyl)amine un­ der medium-dilution...

Transthyretin is an essential protein responsible for the transport of thyroid hormones and retinol in human serum and is also implicated in the amyloid diseases familial amyloidotic polyneuropathy and senile systemic amyloidosis. Its folding properties and stabilization by ligands are of current interest due to their importance in understanding and combating these diseases. Here we report the ...

An affinity-chromatography column was used to isolate and purify 5-hydroxytryptamine (serotonin, 5-HT) receptors from bovine brain frontal cortex. The affinity ligand lysergic acid ethylamidoethylbromide was synthesized and coupled to an agarose matrix via a thioether bond. Receptors in the crude cortical membrane fragments were solubilized using 3-[(3-cholamidopropyl)-dimethylammonio]-1-propan...

Targeting studies using the anti-cancer agent neocarzinostatin (NCS), conjugated to anti-bodies have shown relatively poor specificity. From the literature, it is unclear whether NCS mediates its effects either in conjugated or unconjugated form. In the present work we have used a conjugate of NCS with transferrin, a biological ligand with a well defined endocytic route, to probe these mechanis...