Integrity of N- and C-termini is important for E. coli Hsp31 chaperone activity.

Hsp31 is a stress-inducible molecular chaperone involved in the management of protein misfolding at high temperatures and in the development of acid resistance in starved E. coli. Each subunit of the Hsp31 homodimer consists of two structural domains connected by a flexible linker that sits atop a continuous tract of nonpolar residues adjacent to a hydrophobic bowl defined by the dimerization interface.

A genetic approach for controlling the binding and orientation of proteins on nanoparticles.

Although silver nanoparticles are excellent surface enhancers for Raman spectroscopy, their use to probe the conformation of large proteins at interfaces has been complicated by the fact that many polypeptides adsorb weakly or with a random orientation to colloidal silver. To address these limitations, we sought to increase binding affinity and control protein orientation by fusing a silver-binding dodecapeptide termed Ag4 to the C-terminus of maltose-binding protein (MBP), a well-characterized model protein with little intrinsic silver binding affinity. Quartz crystal microbalance measurements conducted with the MBP-Ag4 fusion protein revealed that its affinity for silver (Kd approximately 180 nM) was at least 1 order of magnitude higher than a control protein, MBP2, containing a non-silver-specific C-terminal extension.

Conformational control of inorganic adhesion in a designer protein engineered for cuprous oxide binding.

Combinatorial selection of peptides that bind technological materials has emerged as a valuable tool for room-temperature nucleation and assembly of complex nanostructured materials. At present, the parameters that control peptide-solid binding are poorly understood, but such knowledge is needed to build the next generation of hybrid materials. Here, we use a derivative of the DNA binding protein TraI engineered with a disulfide-bonded cuprous oxide binding sequence called CN225 to probe the influence of sequence composition and conformation on Cu2O binding affinity.

Air quality status at selected locations in Hyderabad City.

A case study for assessing the air quality status is elaborated for Hyderabad city. Monitoring was carried out at 11 locations during March 2003. These observations on air quality status and AQEI predicts that most of the localities in Hyderabad are experiencing the air pollution stress and the trend is likely to worsen in near future if proper control measures are not implemented.

Identification and characterization of Cu(2)O- and ZnO-binding polypeptides by Escherichia coli cell surface display: toward an understanding of metal oxide binding.

We have used the FliTrx cell surface display system to identify disulfide-constrained dodecapeptides binding to the semiconducting metal oxides Cu(2)O and ZnO. Sequence analysis of the inserts revealed that the two populations exhibit similar, yet subtly different patterns of amino acid usage. Both sets of binders were enriched in arginine, tryptophan, and glycine with a higher degree of positional preference in the case of Cu(2)O binders.

The linker-loop region of Escherichia coli chaperone Hsp31 functions as a gate that modulates high-affinity substrate binding at elevated temperatures.

Precise control of substrate binding and release is essential for molecular chaperones to exert their protective function in times of stress. The mechanisms used are diverse and have been difficult to unravel. Escherichia coli heat-shock protein 31 (Hsp31) is a recent addition to the known complement of eubacterial chaperones.

Hsp31, the Escherichia coli yedU gene product, is a molecular chaperone whose activity is inhibited by ATP at high temperatures.

The Escherichia coli chromosome contains several uncharacterized heat-inducible loci that may encode novel molecular chaperones or proteases. Here we show that the 31-kDa product of the yedU gene is an efficient homodimeric molecular chaperone that is conserved in a number of pathogenic eubacteria and fungi. Heat shock protein (Hsp) 31 relies on temperature-driven conformational changes to expose structured hydrophobic domains that are likely responsible for substrate binding.

Purification of alpha-amylase isoenzymes from Scytalidium thermophilum on a fluidized bed of alginate beads followed by concanavalin A-agarose column chromatography.

An alpha-amylase has been purified from the thermophilic fungus Scytalidium thermophilum. A ninefold purification was achieved in a single step using fluidized bed chromatography wherein alginate was used as the affinity matrix. There are at least two isoenzymes as shown by concanavalin A (Con A)-agarose column chromatography.

Bond and molecular polarizabilities in the reactivity studies of uracil and its substituents.

Bond and molecular polarizabilities of uracil and its substituents are determined by molecular vibration and quantum mechanical delta-function potential model. The longitudinal bond polarizability coefficients of C4-C5, C5-CH3 and C5-NO2 bonds confirm that position 5 is partially aromatic while position 4 is aliphatic with reference to the reactivity nature of carbon atoms in uracil. The results are discussed in relation to experimental and theoretical results.

Comparative pharmacokinetic evaluation of compressed naproxen suppositories in humans.

Compressed naproxen (CAS 22204-53-1) suppositories (250 mg) were formulated by dispersing the drug in molten polyethylene glycol 4000 followed by congealing and pulverizing the mass into granules and then compressing into suppositories. Their pharmacokinetic performance was evaluated and compared with that of a standard naproxen tablet in 12 healthy human volunteers. There were no statistically significant (p > 0.

Comparative evaluation of ulcer prevention efficacy of orally, rectally and sublingually administered omeprazole in three acute gastric ulcer models in rats.

Ulcer prevention efficacy of orally, rectally and sublingually administered omeprazole was evaluated and compared using ulcer index and percentage inhibition of ulcerogenicity in three different acute gastric ulcer models viz, indomethacin, 0.6N HCl and aspirin (after pylorus ligation) induced ulcers in rats. The ulcer prevention efficacy after oral, rectal and sublingual administration were statistically significant (P < 0.

Potentiation of hypoglycemic response of glibenclamide by piroxicam in rats and humans.

Influence of piroxicam (PX) on glibenclamide (GL) induced hypoglycemia has been studied in rats, healthy human volunteers and diabetics. GL per se has significantly reduced blood sugar levels in rats and in humans. PX per se has significantly reduced BSLs, in diabetics, while having no significant influence on blood sugar level in rats and healthy human volunteers.

Effect of zinc ion on the interaction of some amino acid compounds of copper(II) with hydrogen peroxide.

Reaction of elemental copper and zinc powder mixtures with glycine (NH2.CH2COOH; HA) or aspartic acid (NH2CHCOOHCH2COOH; H2B) (in 1:1:2 ratio, respectively) in the presence of excess hydrogen peroxide (H2O2) at 50 degrees C, results in the formation of a new mixed metal peroxy carbonate compound corresponding to formula [Cu(Zn)2(O2(2-) (CO3)2(H2O)4], while the same reaction with elemental copper powder alone yields merely peroxy amino acid compounds having the formula [Cu(O2(2-)) (HA)2(H2O)] and [Cu(O2(2-)) (H2B) (H2O)2] for glycine and aspartic acid, respectively. These compounds have been characterized by elemental analysis, ESR, and electronic and IR spectra.