Identificationof Small Molecule Inhibitors of HumanAs(III) S-Adenosylmethionine Methyltransferase(AS3MT)

Arsenic is the most ubiquitous environmental toxin and carcinogen. Long-term exposure to arsenic is associated with human diseases including cancer, cardiovascular disease, and diabetes. Human As(III) S-adenosylmethionine (SAM) methyltransferases (hAS3MT) methylates As(III) to trivalent mono- and dimethyl species that are more toxic and potentially more carcinogenic than inorganic arsenic. Modulators of hAS3MT activity may be useful for the prevention or treatment of arsenic-related diseases. Using a newly developed high-throughput assay for hAS3MT activity, we identified 10 novel noncompetitive small molecule inhibitors. In silico docking analysis with the crystal structure of an AS3MT orthologue suggests that the inhibitors bind in a cleft between domains that is distant from either the As(III) or SAM binding sites. This suggests the presence of a possible allosteric and regulatory site in the enzyme. These inhibitors may be useful tools for future research in arsenic metabolism and are the starting-point for the development of drugs against hAS3MT

BIS-cyclic guanidine compound compositions, methods of use and treatment thereof

The present disclosure provides compositions including a bis-cyclic guanidine compound, pharmaceutical compositions including a bis-cyclic guanidine compound, methods of treatment of a condition {e.g., bacterial infection) or disease, methods of treatment using compositions or pharmaceutical compositions, and the like

The Mathematics of a Successful Deconvolution: A Quantitative Assessment of Mixture-Based Combinatorial Libraries Screened Against Two Formylpeptide Receptors

In the past 20 years, synthetic combinatorial methods have fundamentally advanced the ability to synthesize and screen large numbers of compounds for drug discovery and basic research. Mixture-based libraries and positional scanning deconvolution combine two approaches for the rapid identification of specific scaffolds and active ligands. Here we present a quantitative assessment of the screening of 32 positional scanning libraries in the identification of highly specific and selective ligands for two formylpeptide receptors. We also compare and contrast two mixture-based library approaches using a mathematical model to facilitate the selection of active scaffolds and libraries to be pursued for further evaluation. The flexibility demonstrated in the differently formatted mixture-based libraries allows for their screening in a wide range of assays

The degradation of dynorphin A in brain tissue in vivo and in vitro

The demonstration of analgesia following in vivo administration of dynorphin A (Dyn A) has been difficult. In contrast, a number of electrophysiological and behavioral effects reported with in vivo injection of Dyn A can be produced by des-tyrosine dynorphin A (Dyn A 2-17). This suggested the extremely rapid amino terminal degradation of dynorphin A. To test this hypothesis, we examined the degradation of dynorphin A following in vivo injection into the periaqueductal gray (PAG) as well as in vitro using rat brain membranes under receptor binding conditions. In vivo, we observed the rapid amino terminal cleavage of tyrosine to yield the relatively more stable destyrosine dynorphin A. This same cleavage after tyrosine was observed in vitro. Inhibition of this aminopeptidase activity in vitro was observed by the addition of dynorphin A 2-17 or dynorphin A 7-17 but not after the addition of dynorphin A 1-13, dynorphin A 1-8, dynorphin B or [alpha]-neo-endorphin suggesting a specific enzyme may be responsible. The detection of the behaviorally active des-tyrosine dynorphin A following in vivo injection of dynorphin A suggests that this peptide may play an important physiological role.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26669/1/0000213.pd

Increased diversity of libraries from libraries: chemoinformatic analysis of bis-diazacyclic libraries

Combinatorial libraries continue to play a key role in drug discovery. To increase structural diversity, several experimental methods have been developed. However, limited efforts have been performed so far to quantify the diversity of the broadly used diversity-oriented synthetic (DOS) libraries. Herein we report a comprehensive characterization of 15 bis-diazacyclic combinatorial libraries obtained through libraries from libraries, which is a DOS approach. Using MACCS keys, radial and different pharmacophoric fingerprints as well as six molecular properties, it was demonstrated the increased structural and property diversity of the libraries from libraries over the individual libraries. Comparison of the libraries to existing drugs, NCI Diversity and the Molecular Libraries Small Molecule Repository revealed the structural uniqueness of the combinatorial libraries (mean similarity < 0.5 for any fingerprint representation). In particular, bis-cyclic thiourea libraries were the most structurally dissimilar to drugs retaining drug-like character in property space. This study represents the first comprehensive quantification of the diversity of libraries from libraries providing a solid quantitative approach to compare and contrast the diversity of DOS libraries with existing drugs or any other compound collection

Binding of [3H]dynorphin a to apparent [kappa] opioid receptors in deep layers of guinea pig cerebral cortex

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24905/1/0000332.pd

[3H]dynorphin a binding and [kappa] selectivity of prodynorphin peptides in rat, guinea-pig and monkey brain

We have previously demonstrated that [3H]dynorphin A selectively labels [kappa] opioid receptors in guinea-pig whole brain. In these current studies, using protection from inactivation by [beta]-chloronaltrexamine ([beta]-CNA), we are able to demonstrate that although dynorphin A prefers [kappa] receptors, it will label [mu] receptors when [kappa] receptors are not available, or present in only a small number. Thus, differences in numbers of [mu] and [kappa] receptors present in brain preparations are critical in determining the receptor binding profile of [3H]dynorphin A across species. Additionally, lthough all the prodynorphin derived peptides show [kappa] preference, the ability of the other prodynorphin derived peptides to compete with [3H]dynorphin A for its receptor varies across species. Consequently, in a highly enriched [kappa] preparation such as monkey cerebral cortex, [3H]dynorphin A appears to label [kappa] receptors with substantial selectivity, and the other prodynorphin-derived peptides show less ability to compete with dynorphin A for its receptor. In contrast, in a [kappa]-poor tissue such as rat brain, all of the prodynorphin-derived peptides, including dynorphin A-(1-8), show very similar potency. Thus, differences in [mu] and [kappa] receptor numbers across brain regions and species lead to differences in the receptor binding profile of dynorphin A.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26234/1/0000314.pd

Prodynorphin peptide immunocytochemistry in rhesus monkey brain

The present study describes the immunocytochemical distribution of peptides derived from the prodynorphin precursor in the brain of the rhesus monkey (Macaca mulatta). Animals were treated with colchicine (intracerebroventricularly) prior to perfusion to enhance the observation of perikaryal immunoreactivity. Using antisera generated against dynorphin A(1-17), dynorphin B(1-13), and prodynorphin(186-208) (or bridge peptide), the anatomical distribution of dynorphin systems was mapped. The results indicate a widespread neuronal localization of immunoreactivity from the cerebral cortex to the caudal medulla. Anti-dynorphin B and anti-bridge peptide sera proved useful for the demonstration of neuronal perikarya, while the dynorphin A antiserum was best for localizing terminal projection fields. Immunoreactive perikarya are located in numerous brain loci, including the cingulate cortex, caudate nucleus, amygdala, hypothalamus (especially the magnocellular nuclei), thalamus, substantia grisea centralis, parabrachial nucleus, nucleus tractus solitarius, and other nuclei. In addition, fiber and terminal immunoreactivity are seen in varying densities in the striatum and pallidum, substantia innominata, hypothalamus, substantia nigra pars reticulata, parabrachial nucleus, spinal trigeminal nucleus, and other areas. The distribution of prodynorphin peptides in the brain of the monkey is similar to that described for the rat brain; however, significant differences also exist. Other interspecies differences in the anatomy of prodynorphin and proenkephalin neuronal systems in the monkey and human brain are further discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25854/1/0000417.pd