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The reforming reactions of greenhouse gases require catalysts with high reactivity, coking resistance, and structural stability for efficient and durable use. Among the possible strategies, exsolution has been shown to demonstrate the requirements needed to produce appropriate catalysts for the dry reforming of methane, the conversion of which strongly depends on the choice of active species, its interaction with the support, and the catalyst size and dispersion properties. Here, we exploit the exsolution approach, known to produce stable and highly active nanoparticle-supported catalysts, to develop iridium-nanoparticle-decorated perovskites and apply them as catalysts for the dry reforming of methane. By studying the effect of several parameters, we tune the degree of exsolution, and consequently the catalytic activity, thereby identifying the most efficient sample, 0.5 atomic % Ir-BaTiO3, which showed 82% and 86% conversion of CO2 and CH4, respectively. By comparison with standard impregnated catalysts (e.g., Ir/Al2O3), we benchmark the activity and stability of our exsolved systems. We find almost identical conversion and syngas rates of formation but observe no carbon deposition for the exsolved samples after catalytic testing; such deposition was significant for the traditionally prepared impregnated Ir/Al2O3, with almost 30 mgC/gsample measured, compared to 0 mgC/gsample detected for the exsolved system. These findings highlight the possibility of achieving in a single step the mutual interaction of the parameters enhancing the catalytic efficiency, leading to a promising pathway for the design of catalysts for reforming reactions. [ABSTRACT FROM AUTHOR]

TNK-tPA products from the innovator and follow-on manufacturers were characterized and compared. All tryptic peptides including N-terminal, C-terminal, and mutated peptides as well as the disulfide-linked peptides were identified, with the demonstration of the same primary sequence and disulfide linkages between the innovator and follow-on products. The three N-linked and one O-linked fucose glycosylation sites were identified. The two N-linked fucose sites (N103 and N448) and one O-linked fucose site (T61) were fully glycosylated in both innovator and follow-on products. The other N-linked site (N184) was partially giycosylated and exhibited a ~2.5-fold difference between the innovator (60% occupancy) and follow-on (25% occupancy) products. Since the glycosylation occupancy at this site is known to affect biological activity in the clot lysis assay, this observed difference could cause a concern as to their bioequivalence. The cleavage site for the conversion of the zymogen form to active enzyme was also identified between R275 and I276, with a cleavage of 40% for the innovator and 10% for the follow-on products. Both the giycosylation occupancy (%) and the chain cleavage (%) were determined by two independent approaches, starting from either the peptide or intact protein separation, with consistent results by both methods. Subtle differences of modifications such as deamidation and oxidation between the innovator and biosimilar products were shown at M207, M445, M490 and N58, N184. The observation of different extents of oxidation at M207 and deamidation at N 184, which could influence the clot lysis activity, were also of potential concern in drug efficacy between the follow-on and innovator products. 10.1021/ac100956x

Recombinant tissue plasminogen (rt-PA) with 35 cysteine residues has been completely assigned by mapping the 17 disulfide linkages and the unpaired cysteine. The result is consistent with the prediction from homology except for the unassigned cysteine, which was identified at Cys83. This cysteine was found to be blocked and paired with either a glutathione or cysteine residue in an ~60:40 ratio, respectively. The analysis was conducted using a multifragmentation approach consisting of electron transfer dissociation (ETD) and collision induced dissociation (CID), in combination with a multienzyme digestion strategy (Lys-C, trypsin, and Glu-C). The disulfide-linked peptides, even those containing N- or O-linked glycosylation, could be assigned since the disulfide bends were still preferably cleaved over the glycosidic cleavages under ETD fragmentation. The use of a multiple and sequential enzymatic digestion strategy was important in producing fragment sizes suitable for analysis. For the analysis of complex intertwined disulfides, the use of [CID-MS.sup.3] to target partially disulfide-dissociated peptides from the ETD fragmentation was necessary for linkage assignment. The ability to identify the exact location and status of the unpaired cysteine (free or blocked with a glutathione or cysteine) could shed light on the activation of rt-PA, upon stimulation by either oxidative or ischemic stress. 10.1021/ac100766r

This publication describes the development of an automated platform for the study of the plasma glycoproteome. The method consists of targeted depletion in-line with glycoprotein fractionation. A key element of this platform is the enabling of high throughput sample processing in a manner that minimizes analytical bias in a clinical sample set. The system, named High Performance Multi-Lectin Affinity Chromatography (HP-MLAC), is composed of a serial configuration of depletion columns containing anti-albumin antibody and protein A with in-line multi-lectin affinity chromatography (M-LAC) which consists of three mixtures of lectins concanavalin A (ConA), jacalin (JAC), and wheat germ agglutinin (WGA). We have demonstrated that this platform gives high recoveries for the fractionation of the plasma proteome ([greater than or equal to] 95%) and excellent stability (over 200 runs). In addition, glycoproteomes isolated using the HP-MLAC platform were shown to be highly reproducible and glycan specific as demonstrated by rechromatography of selected fractions and proteomic analysis of the unbound (glycoproteome 1) and bound (glycoproteome 2) fractions. 10.1021/ac9013308

Three different analysis platforms using LC--MS were successfully developed for pharmacokinetic (PK) studies of an antibody drug in serum. These analysis platforms can be selectively used for different types of protein drugs, which ranged from a very specific for a particular drug (antibody enrichment) to a less specific for any antibody drugs with an Fc domain (protein A enrichment), and to a very generic method that can be used for any protein drugs (albumin depletion method). In this manner, the three platforms will be applicable to a wide range of antibody therapeutic studies for different species. The analysis using an albumin depletion method (with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)) achieved the detection of the drug (to 1 ng) in an aliquot of serum (30 [micro]L) with a 5-order magnitude of linearity. The analysis using protein A enrichment (with SDS-PAGE) achieved the detection of the drug at a 50-fold lower level (to 0.02 ng). Without the use of SDS-PAGE for separation, the use of protein A enrichment achieved the detection to 10 ng and using the antidrug antibody enrichment achieved the detection to 0.1 ng, with a similar linear dynamic range. These three analysis platforms produced good agreement with a mimic PK study of the drug in monkey serum, as compared to the enzyme-linked immunosorbent assay (ELISA) approach. In addition, these analysis platforms can be selectively applied for PK studies of drugs with different requirements of development time and resources. Such as, the antibody enrichment method can be used in a high-throughput manner hut limited to a specific protein drug only. On the other hand, the albumin depletion method can be applied to many types of protein drugs but with the laborious sample preparation steps (SDS-PAGE and the subsequent in-gel digestion). When antidrug antibodies are not available for antibody drugs or the sensitivity requirement is not stringent (e.g., > 10 ng), using protein A enrichment (without using SDS-PAGE) seems to be a good choice for PK studies which require fast throughput. 10.1021/ac901991x

The productivity of mammalian cell culture expression systems is critically important to file production of biopharmaceuticals. In rids study, a high-producing Chinese hamster ovary cell culture which was transfected with the apoptosis inhibitor Bcl-[X.sub.L] gene was compared to a low-producing control that was not transfected. Shotgun proteomics was used to compare the high and low-producing fed-batch cell cultures at different growth time points. The goals of this study were twofold; it would be of value to find a biomaker that could predict cell lines with higher growth efficiency and to gain mechanistic insights into the effects of the introduction of a foreign gene flint is known to have growth regulating properties in human cells. A total of 392 proteins were identified in lifts study, and 32 of these proteins were determined to be differentially expressed. In the high-producing cell culture, several proteins related to protein metabolism were upregulated, such as eukaryotic translation initiation factor 3 and ribosome 40S. In addition, several intermediate filament proteins such as vimentin and annexin, as well as histone H1.2 and H2A, were down-regulated in the high producer. The expression of these proteins may be indicative of cellular productivity. A growth inhibitor, galectin-1, was downregulated in the high producer, which may be linked to the expression of Bcl-[X.sub.L]. The molecular chaperone BiP was upregulated significantly in the high producer and may indicate an unfolded protein response due to endoplasmic reticulum (ER) stress. Several proteins involved in regulation of the cell cycle such as RACK1 and GTPase Ran were found to be differentially expressed, which may be due to a differentially controlled cell cycle between low- and high-producing cell cultures.

In the biotechnology industry, the generation of incorrectly folded recombinant proteins, either from an E.coli expression system or from an overexpressed CHO cell line (disulfide scrambling), is often a great concern as such incorrectly folded forms may not be completely removed in the final product. Thus, significant efforts have been devoted to map disulfide bonds to ensure drug quality. Similar to ECD, disulfide bond cleavages are preferred over peptide backbone fragmentation in ETD. Thus, an online LC-MS strategy combining collision-induced dissociation (CID-[MS.sup.2]), electron-transfer dissociation (ETD-[MS.sup.2]), and CID of an isolated product ion derived from ETD ([MS.sup.3]) has been used to characterize disulfide-linked peptides. Disulfide-linked peptide ions were identified by CID and ETD fragmentation, and the disulfide-dissociated (or partially dissociated) peptide ions were characterized in the subsequent [MS.sup.3] step. The online LC-MS approach is successfully demonstrated in the characterization of disulfide linkages of recombinant human growth hormone (Nutropin), a therapeutic monoclonal antibody, and tissue plasminogen activator (Activase). The characterization of disulfide-dissociated or partially dissociated peptide ions in the [MS.sup.3] step is important to assign the disulfide linkages, particularly, for intertwined disulfide bridges and the unexpected disulfide scrambling of tissue plasminogen activator. The disulfide-dissociated peptide ions are shown to be obtained either directly from the ETD fragmentation of the precursors (disulfide-linked peptide ions) or indirectly from the charge-reduced species in the ETD fragmentation of the precursors. The simultaneous observation of disulfide-linked and disulfide-dissociated peptide ions with high abundance not only provided facile interpretation with high confidence but also simplified the conventional approach for determination of disulfide linkages, which often requires two separate experiments (with and without chemical reduction). The online LC-MS with ETD methodology represents a powerful approach to aid in the characterization of the correct folding of therapeutic proteins.

An improved liquid chromatography tandem mass spectrometry (LC--MS/MS) method has been developed for the determination of tobacco specific nitrosamines (TSNA). It utilizes four stable isotope-labeled internal standards instead of two as reported by others. A separate internal standard for each analyte is required to minimize sample matrix effects on each analyte, which can lead to poor analyte recoveries and decreases in method accuracy and precision if only one or two of the internal standards are used, especially for complex sample matrixes and when no sample cleanup steps are performed as in this study. In addition, two ion-transition pairs (instead of one) are used for each analyte for the confirmation and quantification, further enhancing the method's accuracy and robustness. These improvements have led to a new LC-MS/MS method that is faster, more sensitive, and selective than the traditional methods and more accurate and robust than the published LC--MS/MS methods. The linear range of the method was from 0.2 to 250 ng/mL with a limit of detection of each TSNA varied from 0.027 to 0.049 ng/mL. Good correlations between the results obtained by the new method and the traditional method were observed for the samples studied.

2-Amino-4-nitroaniline crystallizes in a noncentrosymmetric space group giving it significant potential for second-order nonlinear optical properties (NLO) in the bulk. The theoretically predicted NLO properties at the molecular level are confirmed using various methods like X-ray diffraction, conventional and polarized IR spectroscopy, thermal and elemental analysis.

Trapping studies and nanosecond-microsecond time-resolved infrared (TRIR) are used for investigating the nature of the nitrene intermediates formed from the sulfilimine-based precursors. The trapping experiments with substrates such as cis-4-octene has shown that reactivity of the nitrene is through the singlet channel, despite a fairly small energy gap between the singlet ground state and the triplet.

The study explains a novel aryl to aryl palladium migration between the o- and d-positions of biaryls in different organopalladium intermediates, which is normally trapped by either a Heck reaction or by Suzuki cross-coupling using arylboronic acids. The analysis reveals that such a palladium migration can easily be activated or deactivated by choosing the right reaction conditions, as there exists an equilibrium that correlates with C-H acidity of the available arene positions.

Different potential retinoid-based therapies are analyzed from the point of view of drug metabolism and transport to target tissues. Analysis focuses on the endogenous factors that affect the absorption, transport, and metabolism of retinoids.

The importance of contacts between the Tn5 transposase (Tnp) [beta]-loop and the end sequence (ES) for multiple steps of Tn5 transposition is explored. A sequential model is proposed for end cleavage in Tn5 transposition in which the uncleaved paired ends complex (PEC) is not symmetrical and conformational changes are required between the first and second cleavage events and also for final strand transfer step of transportation.

The [alpha.sub.3][(beta[Met.sup.222]Ser/[Tyr.sup.345]Trp).sub.3]gamma double-mutant subcomplex of the [F.sub.1]-ATPase from the thermophilic Bacillus PS3 (T[F.sub.1]), free of nucleotides, does not hydrolyze ATP at a significant rate until the substrate binds to the catalytic site of the lowest affinity.This prevents assessment of the equilibrium at the high-affinity catalytic site when the wild-type [TF.sub.1] subcomplex hydrolyzes substoichiometric ATP.

The construction and design of a microscope coupled with a miniature UV-vis spectrometer is described. This was applied to the study of dyes linked to solid supports and displayed good correlation in spectral shape and [[lambda].sub.max] values when compared to the dyes in solution, as well as showing a linear relationship between dye loading and UV--vis absorbance. The spectral profiles of these dyes at various pH's were measured and used to determine the [pK.sub.a] of the dyes on the beads, which were compared with the [pK.sub.a] values of the dyes in solution, thus enabling the dye-loaded beads to act as pH sensors.

The structures of the [{Os(PPh3)2(pap)}2(ca)](CIO4)2, [Os(PPh3)2(pap)(ca)], and [{Os(PPh3)2(CO)2}2(r-ca)] complexes are determined by X-ray crystallography. In the [{Os(bpy)2}(ca)](super 2+) and [{Os(PPh3)2(pap)2(ca)](super 2+) complexes, the chloranilate dianion is serving as a tetradentate bridging ligand.

Inactivation of the double mutant containing empty catalytic sites or MgADP bound to one catalytic site with CuCl(sub 2) cross-linked when at least two catalytic sites contained MgADP. The catalytic site at the alpha(sub TP)-beta(sub TP) interface with bound MgADP in crystal structures represents a catalytic site containing inhibitory MgADP.

Thirty-three variants of the flavoprotein component of p-cresol methylhydroxylase that contain noncovalently or covalently bound flavin adenine dinucleotide (FAD) analogues were studied. A study that demonstrates clearly that the redox properties of both the bound substrate and the flavin cofactor must be taken in to explain the relative catalytic efficiencies of the variant flavoprotein is presented.

The distinct aspect of the triple molecular pseudorotaxane-like structures is that the visitor resides in the different sections of the cavities of two cryptand molecules. It is identified that the supramolecular cryptands are developed by chelation of a macrocycle, which performs dual role and is capable of enhancing the complexations along with the paraquat offshoots and the diammonium salt.

The structure and energetics of the simplest vic-disulfoxide CH3S(O)S(O)CH3 and its key isomers are reported. The B3LYP structure obtained for 5,5-di-t-butyltetrathiolane-2, 3-dioxide reproduces the essential structural parameters of the known vic-disulfinyl compound, 5-(1-adamantyl)-5-tert-butyltetrathiolane-2,3-dioxide.

The study shows that molecular oxygen reacts with bridging OH (OH(sub br)) groups formed as a result of water dissociation on the surface of rutile TiO2(110). The results suggest the negative influence of high water concentrations in gas-phase.

The eyes in the retinol-binding protein-deficient mice are incapable of meeting their requirement of retinol through uptake of absorbed dietary retinol, which results in the impaired vision phenotype in these mice. In the normal mice, the eyes show preference for acquiring retinol from the retinol-retinol-binding-protein complex.