Experiments are described which have led to the selective alkylation of a histidine residue in streptococcal proteinase without concomitant reaction with the single essential sulfhydry1 group. The reduced, active form of the enzyme was first treated with sodium tetrathionate to protect the sulfhydry1 group and to introduce a negative charge near the active center. The resulting inactive derivat...

A series of seed priming experiments were conducted to test the effects of different pretreatment methods to seed germination, seedling growth, and seed yield traits in maize (Zea mays L.). Results indicated that the seeds primed by gibberellins (GA), NaCl, and polyethylene glycol (PEG) reagents showed a higher imbibitions rate compared to those primed with water. The final germination percenta...

The purpose of this study was to compare quantification of cholesterol in high-density lipoprotein subfractions HDL2 and HDL3 by precipitation with polyethylene glycol (PEG) with that by density-gradient ultracentrifugation. Fresh serum samples from 32 fasting, obese children were analyzed with precipitation reagent "Quantolip" (Immuno AG), and then fractionated with a Beckman TL 100 ultracentr...

This study underscores the development of Ag hydrogel nanocomposites, as smart substrates for antibacterial uses, via innovative in situ reactive and reduction pathways. To this end, two different synthetic strategies were used. Firstly thiol-acrylate (PSA) based hydrogels were attained via thiol-ene and radical polymerization of polyethylene glycol (PEG) and polycaprolactone (PCL). As a second...

The one-pot synthesis of symmetrical triaryl amines using aryl halides and 5-Methyl-1,3,4-Thiadiazole-2-Amine as a nitrogen-transfer reagent is reported. Copper oxide nanoparticles that does not require the presence of any additional ligand, improved rate and facility of the synthesis of triaryl amines. The introduction of a new N-source, using green solvents PEG/H2O, normal atmospheric conditi...

The localization of Cu,Zn-superoxide dismutase in the mitochondrial intermembrane space suggests a functional relationship with superoxide anion (O2*-) released into this compartment. The present study was aimed at examining the functionality of Cu,Zn-superoxide dismutase and elucidating the molecular basis for its activation in the intermembrane space. Intact rat liver mitochondria neither sca...

Inflammatory signaling pathways orchestrate the cellular response to infection and injury. These pathways are known to be modulated by compounds that alkylate cysteinyl thiols. One class of phytochemicals with strong thiol alkylating activity is the chalcones. In this study we tested fourteen chalcone derivatives, α-X-substituted 2',3,4,4'-tetramethoxychalcones (α-X-TMCs, X = H, F, Cl, Br, I, C...

Two alternative methods for the attachment of monomethoxypolyethyleneglycols (PEG) to proteins are proposed; they are based upon the replacement of the hydroxy terminal function of PEG to carboxylate followed by its activation with dicyclohexylcarbodiimide and N-hydroxysuccinimide. The methods, which give more homogeneous product than that employing trichloro-s-triazine as coupling reagent, may...

Changes in redox state are involved in several physiological and pathophysiological processes. Previous experiments have demonstrated that nitric oxide can function as a reactive oxygen species, inhibiting neuronal sodium currents by nitrosylation of thiol residues. We hypothesized that nitric oxide and thiol oxidizers similarly modulate voltage-dependent sodium currents. Voltage-dependent sodi...

Near-infrared (NIR) fluorescence imaging has advanced medical and image-guided interventions during the past three decades. Despite tremendous advances in devices, surprisingly only a few dyes are currently available clinic. Previous fluorophores, ZW800-1A ZW800-1C, significantly improved poor performance of FDA-approved indocyanine green. However, is not stable serum ZW800-1C induces severe st...