The title salt, (C(5)H(6)N)(4)[Mo(2)Cl(2)O(5)(SO(4))(2)], comprises four pyridinium cations for each [(MoClO(2))(2)(μ-O)(μ-SO(4))(2)](4-) anionic unit. The asymmetric unit consists of three aggregates of the empirical formula. The tetra-anionic bimetallic molybdenum(VI) cluster is unprecedented and contains two sulfate and one oxide bridges. This structure constitutes the first example of a non...

The amphipathic antimicrobial peptide piscidin 1 was studied in magnetically aligned phospholipid bilayers by oriented-sample solid-state NMR spectroscopy. (31)P NMR and double-resonance (1)H/(15)N NMR experiments performed between 25 °C and 61 °C enabled the lipid headgroups as well as the peptide amide sites to be monitored over a range of temperatures. The α-helical peptide dramatically affe...

The muscle nicotinic acetylcholine receptor is a large, allosteric, ligand-gated ion channel with the subunit composition alpha2betagammadelta. Although much is now known about the structure of the binding site, relatively little is understood about how the binding event is communicated to the channel gate, causing the pore to open. Here we identify a key hydrogen bond near the binding site tha...

A three-coordinate Cu-NR(2) system (R = p-tolyl) supported by the anionic bis(phosphino)borate ligand [Ph(2)B(CH(2)P(t)Bu(2))(2)](-) has been isolated and structurally characterized in both its anionic Cu(I) and neutral (formally) Cu(II) oxidation states. A large rate constant for the self-exchange electron-transfer reaction (k(S) >or= 10(7) M(-1) s(-1)) makes this system a functional model for...

Air-sensitive complexes [Cu2(μ-phtz)3(PR3)2][CF3SO3]2 (phtz = C8H6N2), 3 (R = phenyl) and 4 (R = benzyl) have been synthesized from {[Cu(CF3SO3)]2·C6H5Me} (1) at room temperature, in acetonitrile solution, after successive additions of stoichiometric amounts of phthalazine (phtz) and triphenylphosphine and tribenzylphosphine, respectively. The dissolution of 4 in an excess of benzyl chloride ga...

Aggregation of presynaptic protein α-synuclein is implicated in the development of Parkinson’s disease. Interaction of α-synuclein with lipid membranes appears to be critical for its physiological and pathological roles. Anionic lipids trigger conformational transition of αsynuclein from its natively disordered into an α-helical structure. Here we used surface plasmon resonance (SPR) to determi...

Anionic phospholipids are largely absent from the external leaflet of the plasma membrane of mammalian cells under normal conditions. Exposure of phosphatidylserine on the cell surface occurs during apoptosis, necrosis, cell injury, cell activation, and malignant transformation. In the present study, we determined whether anionic phospholipids become exposed on tumor vasculature. A monoclonal a...

Inhibition of synaptic acetylcholinesterase (AChE) by organophosphate (OP) nerve agents is the main reason for their toxicity. Oximes are used as antidotes to reactivate nerve agent-inhibited AChE. To understand the mechanism of oxime-induced reactivation, we generated several mutant AChEs. Reactivation studies conducted with wild-type and mutant AChEs revealed that the peripheral anionic site ...

This work reports the covalent immobilization of tetracycline and rolitetracycline over anionic collagen membranes and the drug release studies as an effort to develop a two stage drug release based on diffusion (fast release) and on the rate of membrane biodegradation (slow release). Independent from casting conditions antibiotics incorporated by dispersion were released in the range from 80 t...

The structure of peptidoglycans of Escherichia coli and Bacillus subtilis is similar except for a few minor modifications, but murein (cell wall) structures are extremely different because the major cell wall constituents, anionic polymers, are not attached to peptidoglycans of E. coli but are attached to those of B. subtilis. Thickness of the cell walls in B. subtilis and the presence of an ou...