Search

Development of allosteric inhibitors into efficient drugs is hampered by their indirect mode-of-action and complex structure-kinetic relationships. To enable the design of efficient allosteric drugs targeting the polymerase of hepatitis C virus (NS5B), the interaction characteristics of three non-nucleoside compounds (filibuvir, VX-222, and tegobuvir) inhibiting HCV replication via NS5B have been analyzed. Since there was no logical correlation between the anti-HCV replicative and enzyme inhibitory effects of the compounds, surface plasmon resonance biosensor technology was used to resolve the mechanistic, kinetic, thermodynamic and chemodynamic features of their interactions with their target and their effect on its interaction with RNA. Tegobuvir could not be seen to interact with NS5B at all while filibuvir interacted in a single reversible step (except at low temperatures) and VX-222 in two serial steps, interpreted as an induced fit mechanism. Both filibuvir and VX-222 interfered with the interaction between NS5B and RNA. They competed for binding to the enzyme, suggesting that they had a common inhibition mechanism and identical or overlapping binding sites. The greater anti-HCV replicative activity of VX-222 over filibuvir is hypothesized to be due to a greater allosteric conformational effect, resulting in the formation of a less catalytically competent complex. In addition, the induced fit mechanism of VX-222 gives it a kinetic advantage over filibuvir, exhibited as a longer residence time. These insights have important consequences for the selection and optimization of new allosteric NS5B inhibitors.

BACKGROUND AND PURPOSE The chemokine receptor CXCR3 directs migration of T-cells in response to the ligands CXCL9/Mig, CXCL10/IP-10 and CXCL11/I-TAC. Both ligands and receptors are implicated in the pathogenesis of inflammatory disorders, including atherosclerosis and rheumatoid arthritis. Here, we describe the molecular mechanism by which two synthetic small molecule agonists activate CXCR3. EXPERIMENTAL APPROACH As both small molecules are basic, we hypothesized that they formed electrostatic interactions with acidic residues within CXCR3. Nine point mutants of CXCR3 were generated in which an acidic residue was mutated to its amide counterpart. Following transient expression, the ability of the constructs to bind and signal in response to natural and synthetic ligands was examined. KEY RESULTS The CXCR3 mutants D112N, D195N and E196Q were efficiently expressed and responsive in chemotaxis assays to CXCL11 but not to CXCL10 or to either of the synthetic agonists, confirmed with radioligand binding assays. Molecular modelling of both CXCL10 and CXCR3 suggests that the small molecule agonists mimic a region of the ‘30s loop’ (residues 30–40 of CXCL10) which interacts with the intrahelical CXCR3 residue D112, leading to receptor activation. D195 and E196 are located in the second extracellular loop and form putative intramolecular salt bridges required for a CXCR3 conformation that recognizes CXCL10. In contrast, CXCL11 recognition by CXCR3 is largely independent of these residues. CONCLUSION AND IMPLICATIONS We provide here a molecular basis for the observation that CXCL10 and CXCL11 are allosteric ligands of CXCR3. Such findings may have implications for the design of CXCR3 antagonists. LINKED ARTICLE This article is commented on by O'Boyle, pp. 895–897 of this issue. To view this commentary visit http://dx.doi.org/10.1111/j.1476-5381.2011.01759.x

A purification process for the manufacture of a recombinant C-terminus heavy chain fragment from botulinum neurotoxin serotype C [rBoNTC(H(c))], a potential vaccine candidate, has been defined and successfully scaled-up. The rBoNTC(H(c)) was produced intracellularly in Pichia pastoris X-33 using a three step fermentation process, i.e., glycerol batch phase, a glycerol fed-batch phase to achieve high cell densities, followed by a methanol induction phase. The rBoNTC(H(c)) was captured from the soluble protein fraction of cell lysate using hydrophobic charge induction chromatography (HCIC; MEP HyperCel™), and then further purified using a CM 650M ion exchange chromatography step followed by a polishing step using HCIC once again. Method development at the bench scale was achieved using 5-100mL columns and the process was performed at the pilot scale using 0.6-1.6L columns in preparation for technology transfer to cGMP manufacturing. The process yielded approximately 2.5 g of rBoNTC(H(c))/kg wet cell weight (WCW) at the bench scale and 1.6 g rBoNTC(H(c))/kg WCW at the pilot scale. The purified rBoNTC(H(c)) was stable for at least 3 months at 5 and -80°C as determined by reverse phase-HPLC and SDS-PAGE and was stable for 24 months at -80 °C based on mouse potency bioassay. N-Terminal amino acid sequencing confirmed that the N-terminus of the purified rBoNTC(H(c)) was intact.

The one-pot, microwave-assisted synthesis of 5-thia-4b,10-diaza-indeno[2,1-a]indene-5,5-dioxide (6) and 10H-11-thia-5,10a-diaza-benzo[b]fluorene-11,11-dioxide (7) from 1,2-phenylenediamine and 2-aminobenzylamine, respectively, is described. Generation of a sulfonamide through reaction of the appropriate diamine with 2-cyanobenzenesulfonyl chloride is followed by a multistep intramolecular transformation and subsequent elimination of ammonia to provide the corresponding tetracycle in good yield.

The adsorption of recombinant botulinum neurotoxin (BoNT) protein-derived vaccine antigens to aluminum salt adjuvants has been previously studied for the development of a trivalent vaccine against the neurotoxins (Vessely et al., in press, J Pharm Sci). The current paper describes an investigation of the stability of recombinant BoNT antigens adsorbed to aluminum salt adjuvants during storage in aqueous solution. Both chemical and physical changes occurred during storage. Phosphate groups in the buffer exchanged with hydroxyl groups on the adjuvant surface. The resulting changes in solution pH and adjuvant surface chemistry promoted more favorable electrostatic interaction between the BoNT proteins and the surface, possibly increasing the affinity of the proteins for the surface during storage. Fluorescence and UV spectroscopy suggested changes to protein structure during storage, whereas differential scanning calorimetry showed changes to thermal processes related to protein conformation and/or surface adsorption. The consequence of the chemical and physical changes to the proteins was a decrease in the ability to desorb protein from the adjuvant surface during storage. Overall, the results of this study emphasize the utility of a thorough characterization of the interactions between protein antigens and aluminum salt adjuvants.

We identified a series of structurally novel SCD (Delta9 desaturase) inhibitors via high-throughput screening and follow-up SAR studies. Modification of the central bicyclic scaffold has proven key to our potency optimization effort. The most potent analog (8g) had IC(50) value of 50 pM in a HEPG2 SCD assay and has been shown to be metabolically stable and selective against Delta5 and Delta6 desaturases.

Highly potent and selective 4-amidofuran-3-one inhibitors of cathepsin S are described. The synthesis and structure-activity relationship of a series of inhibitors with a sulfonamide moiety in the P3 position is presented. Several members of the series show sub-nanomolar inhibition of the target enzyme as well as an excellent selectivity profile and good cellular potency. Molecular modeling of the most interesting inhibitors describes interactions in the extended S3 pocket and explains the observed selectivity towards cathepsin K.

A general solid-phase synthesis of 1,2,5-trisubstituted imidazolidin-4-ones is described. The key synthetic transformation incorporates a microwave-assisted condensation of an α-amino amide on solid support with an aldehyde in solution to give the corresponding resin-bound imidazolidin-4-one in a simple one-pot procedure.

A process was developed for production of a candidate vaccine antigen, recombinant C-terminal heavy chain fragment of the botulinum neurotoxin serotype E, rBoNTE(H(c)) in Pichia pastoris. P. pastoris strain GS115 was transformed with the rBoNTE(H(c)) gene inserted into pHILD4 Escherichia coli-P. pastoris shuttle plasmid. The clone was characterized for genetic stability, copy number, and BoNTE(H(c)) sequence. Expression of rBoNTE(H(c)) from the Mut(+) HIS4 clone was confirmed in the shake-flask, prior to developing a fed-batch fermentation process at 5 and 19 L scale. The fermentation process consists of a glycerol growth phase in batch and fed-batch mode using a defined medium followed by a glycerol/methanol transition phase for adaptation to growth on methanol and a methanol induction phase resulting in the production of rBoNTE(H(c)). Specific growth rate, ratio of growth to induction phase, and time of induction were critical for optimal rBoNTE(H(c)) production and minimal proteolytic degradation. A computer-controlled exponential growth model was used for process automation and off-gas analysis was used for process monitoring. The optimized process had an induction time of 9 h on methanol and produced up to 3 mg of rBoNTE(H(c)) per gram wet cell mass as determined by HPLC and Western blot analysis.

This is the first report of 5-styryl-oxathiazol-2-ones as inhibitors of the Mycobacterium tuberculosis (Mtb) proteasome. As part of the study, the structure–activity relationship of oxathiazolones as Mtb proteasome inhibitors has been investigated. Furthermore, the prepared compounds displayed a good selectivity profile for Mtb compared to the human proteasome. The 5-styryl-oxathiazol-2-one inhibitors identified showed little activity against replicating Mtb, but were rapidly bactericidal against nonreplicating bacteria. (E)-5-(4-Chlorostyryl)-1,3,4-oxathiazol-2-one) was most effective, reducing the colony-forming units (CFU)/mL below the detection limit in only seven days at all concentrations tested. The results suggest that this new class of Mtb proteasome inhibitors has the potential to be further developed into novel antitubercular agents for synergistic combination therapies with existing drugs.

The identification and evaluation of aryl-[1,4]diazepane ureas as functional antagonists of the chemokine receptor CXCR3 are described. Specific examples exhibit IC(50) values of approximately 60 nM in a calcium mobilization functional assay, and dose-dependently inhibit CXCR3 functional response to CXCL11 (interferon-inducible T-cell alpha chemoattractant/I-TAC) as measured by T-cell chemotaxis, with a potency of approximately 100 nM.

Purpose.The purpose of this study was to investigate the physicochemical and structural characteristics of recombinant botulinum serotype B (rBoNTB(Hc)) under various conditions and to use the information in evaluating suitable purification process conditions. Methods. The solubility of rBoNTB(Hc) was evaluated at pH 4, 5, 6 7.5, 8, and 9. Secondary structure was evaluated using circular dichroism, and conformational stability was monitored using high-sensitivity differential scanning calorimetry. Hydrophobic interaction chromatography, size exclusion chromatography-high performance liquid chromatography (SEC-HPLC), sodium dodecyl sulfate-poly acrylamide gel electrophoresis (SDS-PAGE), peptide mapping, and UV spectroscopy were used to monitor stability under the various conditions. Results. The secondary structure of rBoNTB(Hc) consists predominantly of β-sheets. Solubility of rBoNTB(Hc) was lowest at its pI and highest at low and high pH. In the presence of NaCl, however, solubility decreased with increase in pH. Conformational and chemical stability are improved below pH 7.5. In the presence of 150 mM NaCl at high pH, conformational and chemical stability of rBoNTB(Hc) are further decreased. The study suggests that the purification process should minimize exposure of rBoNTB(Hc) to high pH and salt conditions. Conclusions. Optimal stability of rBoNTB(Hc) is achieved at low pH. The biophysical and analytical studies provide us with an understanding of rBoNTB(Hc) stability behavior in solution and assists in developing efficient purification conditions.

Structural conversion of the serotype A recombinant botulinum neurotoxin heavy chain fragment (rBoNTA(Hc)) produced intracellularly in Pichia pastoris yeast was observed and characterized during purification development efforts. A pH screening study captured the transformation stages of the original recovered species into its derived counterpart and a number of analytical tools such as peptide mapping by LC/MS confirmed the formation of a disulfide bond, especially in samples of neutral to basic pH. A cation exchange chromatographic method proved useful in following the incidence of the reaction in various rBoNTA(Hc) samples. The disulfide formation kinetics were characterized using a one-quarter quadratic factorial design, following the investigation and development of controlled oxidation conditions using cysteine and cystamine as the redox pair. Temperature, pH and concentration of the redox pair had a significant effect on the yield and rate of the disulfide formation. This controlled reaction was eventually introduced as a functional unit operation in the purification process. The summation of preliminary scale-up and potency data showed scalability and robustness in the production of an active disulfide-bonded form of a recombinant botulism vaccine candidate. The presence of the disulfide bond did not effect the vaccine potency and it enhanced the molecule's thermal stability.

Initial purification of two serotypic variants of recombinant botulinum neurotoxin toxin heavy chain fragment [rBoNT(Hc)], produced intracellularly in the yeast Pichia pastoris, using hydrophobic charge induction chromatography (HCIC) is reported. HCIC employs a matrix containing a weakly ionizable ligand that binds proteins through hydrophobic interactions at neutral pH and elutes the proteins by charge repulsion at acidic pH. HCIC optimization led to different purification conditions for each of the proteins even though they have 58% sequence similarity. The HCIC resin has a higher affinity for the fragment of serotype A than that of serotype B. The 10% dynamic breakthrough capacity for the serotype A fragment is >12.5 mg per ml of resin and is approximately 3.5 mg or the serotype B fragment per ml of resin. Stable elution conditions are also different for the two serotypes. The serotype A fragment is unstable when citrate is used to elute the product. However the serotype B fragment is stable when eluted with citrate buffer, and it is further purified by a overnight precipitation caused by the citrate buffer. This paper reports the development strategy, dynamic capacity breakthrough curves, resin and separation reproducibility, and preliminary scale-up data. The summation of the data demonstrates that HCIC is a scaleable process step for biopharmaceutical production of rBoNT(Hc) proteins.

The cysteinyl proteinase cathepsin S is implicated as a key enzyme in the processing of major histocompatability complex (MHC) class II molecules expressed on antigen presenting cells and thus is a potential therapeutic target for modulation in immune system-based disease. We have identified a form of rat cathepsin S, similar to a published mouse form with an eight-amino acid extended presequence relative to the human enzyme and the previously published rat enzyme. In addition, we have expressed these mouse and rat proteins in baculovirally infected Sf9 insect cells along with "humanized" forms truncated by eight residues at the amino-terminus. All forms of the rodent proteinases were overexpressed and milligram per litre amounts of functional enzyme could be isolated from the cells and/or the cell culture supernatant. Furthermore, addition of a carboxy-terminal hexahistidine purification tag had no effect on the kinetic characteristics of any of the enzyme forms against the Boc-Val-Leu-Lys-AMC peptide substrate (rat k(cat) s(-1) approximately 30; mouse k(cat) s(-1) approximately 65). Differences were seen in the potency of the generic cysteine proteinase inhibitor, E64, against the human, mouse, or rat form of the enzyme (13.3 x 10(4), 43.2 x 10(4), and 25 x 10(4) K(obe)/[I] M(-1) s(-1), respectively). Such data highlights the need for greater awareness of species variation in inhibitor potency. These reagents are vital for confirming inhibitor potency against the endogenous form of the enzyme prior to evaluation of drug candidates in rodent model systems.

A variety of small-molecule combinatorial libraries have been prepared on solid support using a binary encoding strategy employing non-sequenceable encoding molecules. Library members are attached to the support using photolabile linkers which permit their release for assay free in solution. The encoding molecules are attached using a carbene insertion reaction and are released via oxidation. A wide variety of synthetic reactions have been utilized for library synthesis including, for example, cyclocondensations, reductive aminations, and heteroaromatic halide displacements, as well as acylations and sulfonylations. Initial screening of two such libraries identified lead structures for the inhibition of carbonic anhydrase. Subsequently, based upon these leads a smaller focused combinatorial library was constructed and used to analyze the structure-activity relationships (SARs) governing enzyme inhibition and isozyme selectivity. The combination of random screening with a broad diversity of compounds, followed by focused libraries for detailed SARs and selectivity, demonstrates the power of binary encoded small-molecule combinatorial libraries for drug discovery.

A chemoenzymatic approach for the synthesis of homoazasugars is described, utilizing an aldolase to catalyze the key asymmetric aldol addition reaction. This approach is illustrated by the synthesis of β-D-homomannonojirimycin (11) using D-fructose diphosphate (FDP) aldolase.

Two methods are presented for kinetic resolutions of compounds containing ester and sulfoxide functionalities (sulfinylalkanoates). In the first a crude lipase preparation from Pseudomonas sp. (K10) mediates enantioselective hydrolysis of these esters in an aqueous environment. The second method uses the same lipase preparation to promote enantioselective transestesterifications with alcohols in hexane

A chemoenzymatic approach for the synthesis of homoazasugars is described, utilizing an aldolase to catalyze the key asymmetric aldol addition reaction. This approach is illustrated by the synthesis of β-D-homomannonojirimycin (11) using D-fructose diphosphate (FDP) aldolase.

The one-pot, microwave-assisted synthesis of 5-thia-4b,10-diaza-indeno[2,1-a]indene-5,5-dioxide (6) and 10H-11-thia-5,10a-diaza-benzo[b]fluorene-11,11-dioxide (7) from 1,2-phenylenediamine and 2-aminobenzylamine, respectively, is described. Generation of a sulfonamide through reaction of the appropriate diamine with 2-cyanobenzenesulfonyl chloride is followed by a multistep intramolecular transformation and subsequent elimination of ammonia to provide the corresponding tetracycle in good yield.

The following three stereoisomers of castanospermine have been prepared: (1R,6R,7R,8S,8aR)-1,6,7,8-tetrahydroxyindolizidine (1), (1R,6S,7S,8S,8aR)-1,6,7,8-tetrahydroxyindolizidine (2), and (1R,6R,7S,8S,8aR)-1,6,7,8-tetrahydroxyindolizidine (3). Each of these compound was synthesized via asymmetric allylation of pentose derivatives with [(Z)-γ-(methoxyinethoxy)allyl]diisopinocampheylborane, an approach which is, in principle, suitable for preparations of a total of eight stereoisomers of castanospermine

Two methods are presented for kinetic resolutions of compounds containing ester and sulfoxide functionalities (sulfinylalkanoates). In the first a crude lipase preparation from Pseudomonas sp. (K10) mediates enantioselective hydrolysis of these esters in an aqueous environment. The second method uses the same lipase preparation to promote enantioselective transestesterifications with alcohols in hexane

We discovered a structurally novel SCD (Delta9 desaturase) inhibitor 4a (CVT-11,563) that has 119 nM potency in a human cell-based (HEPG2) SCD assay and selectivity against Delta5 and Delta6 desaturases. This compound has 90% oral bioavailability (rat) and excellent plasma exposure (dAUC 935 ng h/mL). Additionally, 4a shows moderately selective liver distribution (three times vs plasma and adipose tissue) and relatively low brain penetration. In a five-day study (high sucrose diet, rat) compound 4a significantly reduced SCD activity as determined by GC analysis of fatty acid composition in plasma and liver. We describe the discovery of 4a from HTS hit 1 followed by scaffold replacement and SAR studies focused on DMPK properties.

4-Chlorophenylsulfinylacetates of defined stereochemistry at sulfur were prepared from monochiral alcohols: compound 2 from (+)-menthol; 3 and 4 from (−)-8-phenylmenthol; 5 and 6 from (+)-trans-2-phenylcyclohexanol; and, 7 and 9 from (-)-10-dicyclohexylsulfamoyl-D-isoborneol. Reagents for which the sulfoxide asymmetry is matched with the inducing effect of the auxiliary give good diastereoselection in SPAC reactions affording γ-hydroxy-α,β-unsaturatod alcohols of high optical purity. Asymmetry at the sulfoxide has a greater effect than the auxiliaries on the stereochemical outcome of these reactions.

Factors that govern chemical and optical yields of methyl γ-hydroxy-α,β-unsaturated esters 1 formed in reactions of optically active sulfinylacetates 2 with aldehydes (the «SPAC» reaction) are defined. Racemic samples of these chirons (1) can be resolved via acylations mediated by crude preparations of the lipase Pseudomonas K-10 in organic solvents. Combinations of asymmetric SPAC reactions with these biocatalytic resolutions provide routes to highly optically active esters 1 in good yields. This methodology is applied in a completely asymmetric synthesis of (4S-cis)-5-(cyclohexylmethyl)-4-hydroxy-2-pyrrolidinone (15), a cyclic derivative of (3S,4S)-4-amino-5-cyclohexyl-3-hydroxypentanoic acid (ACHPA)

A series of trisubstituted purinones was synthesized and evaluated as A(2A) receptor antagonists. The A(2A) structure-activity relationships at the three substituted positions were studied and selectivity against the A(1) receptor was investigated. One antagonist 12o exhibits a K(i) of 9nM in an A(2A) binding assay, a K(b) of 18nM in an A(2A) cAMP functional assay, and is 220-fold selective over the A(1) receptor.

The discovery and synthesis of a series of 2-amino-5-benzoyl-4-(2-furyl)thiazoles as adenosine A2A receptor antagonists from a small-molecule combinatorial library using a high-throughput radioligand-binding assay is described. Antagonists were further characterized in the A2A binding assay and an A1 selectivity assay. Selected examples exhibited excellent affinity for A2A and good selectivity versus the A1 receptor.

The synthesis and identification of sulfonamido-aryl ethers as potent bradykinin B1 receptor antagonists from a approximately 60,000 member encoded combinatorial library are reported. Two distinct series of compounds exhibiting different structure-activity relationships were identified in a bradykinin B1 whole-cell receptor-binding assay. Specific examples exhibit K(i) values of approximately 10nM.

The discovery and synthesis of a series of (dimethoxyphenoxy)alkylamino acetamides as orexin-2 receptor antagonists from a small-molecule combinatorial library using a high-throughput calcium mobilization functional assay (HEK293-human OX2-R cell line) is described. Active compounds show a good correlation between high-throughput single concentration screening data and measured IC(50)s. Specific examples exhibit IC(50) values of approximately 20 nM using human orexin A as the peptide agonist for the orexin-2 receptor.

(1S, 2R, 7R, 7aR)- 1,2,7-Trihydroxypyrrolizidine ( 1 ) is prepared by elaboration of an erythrose derivative ( 4 ) via an asymmetric allylation reaction; this approach promises to be widely applicable to syntheses of polyhydroxylated indolizidine and pyrrolizidine alkaloids.

γ-Hydroxy-α,β-unsaturated compounds ( 3 ) (SPAC creation products) are resolved via irreversible biocatalytic acylations; this process can be used in series with asymmetric SPAC reactions to improve optical purities.

Botulinum neurotoxin (BoNT) is a biological warfare threat. Protein antigens have been developed against the seven major BoNT serotypes for the development of a recombinant protein vaccine. This study is an evaluation of adsorption profiles for three of the recombinant protein antigens to aluminum salt adjuvants in the development of a trivalent vaccine against BoNT. Adsorption profiles were obtained over a range of protein concentrations. The results document that charge-charge interactions dominate the adsorption of antigen to adjuvant. Optimal conditions for adsorption were determined. However, potency studies and solution stability studies indicated the necessity of using aluminum hydroxide adjuvant at low pH. To improve the adsorption profiles to AlOH adjuvant, phosphate ions were introduced into the adsorption buffers. The resulting change in the adjuvant chemistry led to an improvement of adsorption of the BoNT antigens to aluminum hydroxide adjuvant while maintaining potency. Competitive adsorption profiles were also determined, and showed changes in maximum adsorption from mixed solutions compared to adsorption from individual protein solutions. The adsorption profiles for each protein varied due to differences in adsorption mechanism and affinity for the adjuvant surface. These results emphasize the importance of evaluating competitive adsorption in the development of multivalent vaccine products.

The discovery and evaluation of 5-(4-phenylbenzyl)oxazole-4-carboxamides as prostacyclin (IP) receptor antagonists is described. Analogs disclosed showed high affinity for the IP receptor in human platelet membranes with IC50 values of 0.05–0.50 μM, demonstrated functional antagonism by inhibiting cAMP production in HEL cells with IC50 values of 0.016–0.070 μM, and exhibited significant selectivity versus other prostanoid receptors.

In a high-throughput screen of four million compounds from combinatorial libraries for small-molecule modulators of the chemokine receptor CXCR3, two classes of receptor agonists, based on tetrahydroisoquinoline and piperidinyl diazepanone templates, were identified. Several of these compounds stimulated calcium flux in HEK293 cells expressing the recombinant human CXCR3 receptor with efficacies and kinetics similar to those of native ligand CXCL11/I-TAC and stimulated chemotaxis of activated human T-cells. The agonist small molecules also inhibited binding of another CXCR3 ligand, CXCL10/IP-10, to the receptor. The response to small-molecule agonists was inhibited by a CXCR3-specific small-molecule antagonist previously identified within the same combinatorial compound collection but structurally unrelated to the agonists. Remarkably, while other, non-amino acid substituents were present in the majority of the library compounds screened, the agonists from both classes contained a positively charged amino acid component, with preference for Arg>Lys, as well as a hydrophobic component.

The p38 mitogen-activated protein (MAP) kinases are a family of serine/threonine protein kinases that play important roles in cellular responses to inflammation and external stress. Inhibitors of the p38 MAP kinase have shown promise for potential treatment of inflammatory disorders such as rheumatoid arthritis, acute coronary syndrome, psoriasis, and Crohn's disease. We identified a novel class of p38 inhibitors via high-throughput screening. PS200981 [3-(4-(1,4-diazepan-1-yl)-6-(((1S,2R,5S)-6,6-dimethylbicyclo[3.1.1]heptan-2-yl)methylamino)-1,3,5-triazin-2-ylamino)-4-methylbenzamide], a representative compound identified from screening a collection of combinatorial libraries, amounting to 2.1 million compounds, inhibits p38alpha kinase and the lipopolysaccharide (LPS)-induced increase in tumor necrosis factor (TNF) alpha levels in cell media of human monocytes with IC50 values of 1 microM. The screening data revealed a preferred synthon, 3-amino-4-methyl benzamide, which is critical for the activity against p38. This synthon appeared almost exclusively in screening hits including PS200981, and slight variations of this synthon including 3-amino benzamide and 2-amino-4-methyl benzamide also contained in the library were inactive. PS200981 is equally potent against the alpha and beta forms of p38 but did not inhibit p38 gamma and is25-fold selective versus a panel of other kinases. PS200981 inhibited the LPS-induced increase in TNFalpha levels when administered at 30 mg/kg to mice. Selectivity and in vivo activity of this class of p38 inhibitors was further demonstrated by PS166276 [(R)-3-(4-(isobutyl(methyl)-amino)-6-(pyrrolidin-3-ylamino)-1,3,5-triazin-2-ylamino)-4-methylbenzamide], a highly structurally related but more potent and less cytotoxic inhibitor, in several intracellular signaling assays, and in LPS-challenged mice. Overall, this novel class of p38 inhibitors is potent, active in vitro and in vivo, and is highly selective.

A novel class of 5-cyanopyrimidine-based inhibitors of p38alpha MAP kinase has been investigated. Analogues optimized through SAR iterations display low nanomolar enzymatic and cellular activity. The in vivo efficacy of this class of p38 inhibitors was demonstrated by 3a and 3b (>50% reduction in TNF levels when orally dosed at 5 mg/kg, 5 h prior to LPS administration in an acute murine model of inflammation). For 3a and 3b, the previously identified N-methoxybenzamide moiety (1) was replaced with N-(isoxazol-3-yl)benzamide, thereby providing increased metabolic stability. Cyanopyrimidine 3a demonstrated 100% oral bioavailability in mouse. High p38 kinase selectivity versus over 20 kinases was observed for analogue 3b. Direct hydrogen bonding of the cyano nitrogen of the 5-cyanopyrimidine core to the backbone NH of Met109 was confirmed by X-ray crystallographic analysis of 3a bound to p38alpha.

A recombinant C-terminus heavy chain fragment from botulinum neurotoxin serotype E (BoNT/E) is proposed as a vaccine against the serotype E neurotoxin. This fragment, rBoNTE(Hc), was produced intracellular in Pichia pastoris GS115 by a three-step fermentation process, i.e., glycerol batch phase and a glycerol fed-batch phase to achieve high cell densities, followed by a methanol fed-batch induction phase. The rBoNTE(Hc) protein was puriWed from the soluble fraction of cell lysates using three ion-exchange chromatography steps (SP Sepharose Fast Flow, Q Sepharose Fast Flow, Sp Sepharose High Performance) and polished with a hydrophobic charge induction chromatography step (MEP HyperCel). Method development at the bench scale was achieved using 7– 380 mL columns and the process was performed at the pilot scale using 0.5–3.1 L columns in preparation for technology transfer to cGMP manufacturing. The puriWcation process resulted in greater than 98% pure rBoNTE(Hc) based on HPLC and yielded up to 1.01 g of rBoNTE(Hc)/kg cells at the bench scale and 580 mg vaccine/kg cells at the pilot scale. N-terminal sequencing showed that the puriWed rBoNTE(Hc) N-terminus is intact and was found to protect mice against a challenge of 1000 mouse intraperitoneal LD50’s of BoNT/E.

Powerlase has made significant steps forward in developing reliable and cost-effective, kilowatt-class laser modules with short pulse duration and small footprint, for use as EUV drivers. These characteristics in parallel to EUV target requirements are essential for the generation of 115W of in-band EUV power at the intermediate focus. These laser modules can be coupled to the EUV target by using our flexible spatial and temporal multiplexing approach in order to scale up the laser average power on target. The multiplexing method developed by Powerlase is modular and optimised for maximum EUV collection angle. To further this goal we are currently evaluating target materials such as xenon in various phases and forms and also have a programme in place to investigate suitable tin targets.

A new structural class of triaminotriazine aniline amides possessing potent p38 enzyme activity has been discovered. The initial hit (compound 1a) was identified through screening the Pharmacopeia ECLiPS compound collection. SAR modification led to the identification of a short acting triaminotriazine aniline methoxyamide (compound 1m) possessing in vitro and in vivo oral activity in animal models of acute and chronic inflammatory disease. An X-ray crystal structure of compound 1m in this class, cocrystallized with unactivated p38 alpha protein, indicates that these compounds bind to the ATP binding pocket and possess key H-bonding interactions within a deeper cleft. Hydrogen bonding between one of the triazine nitrogens and the backbone NH of the Met109 residue occurs through a water molecule. The methoxyamide NH and carbonyl oxygen are within H-bonding distance of Glu71 and Asp168.

Laser milling of a variety of substrates is investigated with the intention of achieving high quality material removal to create three-dimensional shapes in the material. A high power Q-switched Diode Pumped Solid State Nd:YAG Laser at 1064nm is used in all cases. Materials investigated include Nickel Superalloys, Thermal Barrier Coatings, Steels, Tungsten Carbide and Polycrystalline Diamond. Multi-layer substrates are also considered. The effects of laser intensity, plasma formation, pulse duration, material properties, and resulting removal rate, recast and surface finish are explored for this process. This paper defines the findings of this study within the context of commercial imperatives.

Heavy chain fragments of botulinum neurotoxin serotypes A and B are being developed as a bivalent vaccine for botulism. To potentiate the immune response, an aluminum containing adjuvant will be formulated with the two antigens. The adsorption mechanisms of each antigen to aluminum phosphate and aluminum hydroxide adjuvants were studied. The adsorption of the serotype A antigen to each adjuvant, and the serotype B antigen to aluminum phosphate adjuvant, is dependent on electrostatic attractive forces. The serotype A antigen is basic, and pretreatment with phosphate anions is required for favorable adsorption conditions to aluminum hydroxide adjuvant. In contrast, the serotype B antigen displays a high affinity to aluminum hydroxide adjuvant even when the two species possess the same charge. It is proposed that the serotype B antigen is adsorbed to aluminum hydroxide adjuvant by a ligand exchange mechanism.

Biocatalytic resolutions of methyl sulfinylacetates fford sulfoxides (R)-( 1 ) - ( 6 ) in very high optical yields; the products have been used in a systematic study of the “SPAC” reaction, an asymmetric synthesis of γ-hydroxy-α,β-unsaturated esters.

A general and efficient solid-phase synthesis of N-9-substituted 2,8-diaminopurines from 5-nitrouracil is described. The key synthetic transformation employs a carbodiimide-mediated cyclization of a thiourea. Thiourea formation on solid phase is performed using both thermal and microwave reaction conditions. Regiospecific solution-phase synthesis of key building blocks allows the incorporation of desired substituents at N-9 of the purine nucleus.