Novel P4 truncated tripeptidyl alpha-ketoamides as HCV protease inhibitors

We describe herein the synthesis and evaluation of two series of P-4 truncated tripeptidyl alpha-ketoamides as HCV serine protease inhibitors. The most promising compound disclosed in this communication 7b demonstrated enzyme binding affinity (K(i)) at 0.27 uM.     

A taxonomic reevaluation of Phrynops (Testudines: Chelidae) with the description of two new genera and a new species of Batrachemys

Relationships among turtle species loosely categorized within the South American genus Phrynops are explored. Three once recognized genera (Batrachemys, Mesoclemmys and Phrynops) that were demoted to subgenera, and then synonymized with Phrynops, are demonstrated to warrant full recognition based on morphometric analysis, skull osteology, and mitochondrial and nuclear gene sequencing. Mesoclemmys is resurrected from the synonymy of Phrynops as a monotypic genus including M. gibba. The genus Rhinemys, previously a synonym of Phrynops, is resurrected for the species R. rufipes. Ranacephala gen. nov. is described to include the species R. hogei. The genus Batrachemys is resurrected from the synonymy of Phrynops and includes B. dahli, B. nasuta, B. raniceps, B. tuberculata, and B. zuliae. The taxon vanderhaegei is placed in Bufocephala gen. nov. The genus Phrynops is redefined to include the taxa P. geoffroanus, P. hilarii, P. tuberosus, and P. williamsi. Cladistic analysis of morphological data supports this taxonomy. A new species of Batrachemys is described from the western Amazon region, and is distinguished by having facial markings in juveniles, a relatively wide head, and a flattened shell. The new species, B. heliostemma sp. nov., is sympatric with and most similar to the recently resurrected form Batrachemys raniceps in the upper Amazonian region of Peru and adjacent Brazil, Ecuador, Venezuela, and Colombia. Lastly, morphometric data from living and museum specimens of all species of Batrachemys are presented.     

Phosphorylation of tyrosine 256 facilitates nuclear import of atypical protein kinase C

Herein, we employed a combined approach of molecular modeling and site-directed mutagenesis to address the role of tyrosine phosphorylation in transport of atypical protein kinase C (aPKC) into the nucleus. Computer modeling of the three-dimensional structure of the aPKC catalytic core, reveals that tyrosine 256 (Tyr256) is located at the lip of the activation loop and is conserved among members of the aPKC family, iota/lambda and zeta. Based on these findings, we examined whether tyrosine phosphorylation of aPKC on the activation lip may facilitate nuclear import. An antiserum was generated that selectively recognizes the phosphorylated Tyr256 residue in aPKC. By isolating nuclei of PC12 cells and immunoprecipitating aPKC with Ab-PY256, we observed that Tyr256 is rapidly phosphorylated upon NGF treatment prior to entry of aPKC into the nucleus. aPKC was observed to exclusively bind to importin-beta. The interaction between importin-beta and aPKC was enhanced upon tyrosine phosphorylation of aPKC and binding was abrogated when Tyr256 was mutated to phenylalanine. We propose that phosphorylation of aPKC at Tyr256 induces a conformation, whereby, the arginine-rich NLS is exposed, which then binds importin-beta leading to import of aPKC into the nucleus. Altogether, these findings document a novel role for the tyrosine phosphorylation in regulating import of atypical PKC into the nucleus.     

Integrated analysis of multimodal single-cell data

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In Situ Depletion of Pentachlorophenol from Contaminated Soil by Phanerochaete spp

The ability of two white rot fungi to deplete pentachlorophenol (PCP) from soil, which was contaminated with a commercial wood preservative, was examined in a field study. Inoculation of soil containing 250 to 400 μg of PCP g⁻¹ with either Phanerochaete chrysosporium or P. sordida resulted in an overall decrease of 88 to 91% of PCP in the soil in 6.5 weeks. This decrease was achieved under suboptimal temperatures for the growth and activity of these fungi, and without the addition of inorganic nutrients. Since the soil had a very low organic matter content, peat was included as a source of organic carbon for fungal growth and activity. A small percentage (8 to 13%) of the decrease in the amount of PCP was a result of fungal methylation to pentachloroanisole. Gas chromatographic analysis of sample extracts did not reveal the presence of extractable transformation products other than pentachloroanisole. Thus, when losses of PCP via mineralization and volatilization were negligible, as they were in laboratory-scale studies (R. T. Lamar, J. A. Glaser, and T. K. Kirk, Soil Biol. Biochem. 22:433-440, 1990), most of the PCP was converted to nonextractable soil-bound products. The nature, stability, and toxicity of soil-bound transformation products, under a variety of conditions, must be elucidated before use of these fungi in soil remediation efforts can be considered a viable treatment method.     

Genotype-Specific Interaction of Latent TGFβ Binding Protein 4 with TGFβ

Latent TGFβ binding proteins are extracellular matrix proteins that bind latent TGFβ to form the large latent complex. Nonsynonymous polymorphisms in LTBP4, a member of the latent TGFβ binding protein gene family, have been linked to several human diseases, underscoring the importance of TGFβ regulation for a range of phenotypes. Because of strong linkage disequilibrium across the LTBP4 gene, humans have two main LTBP4 alleles that differ at four amino acid positions, referred to as IAAM and VTTT for the encoded residues. VTTT is considered the “risk” allele and associates with increased intracellular TGFβ signaling and more deleterious phenotypes in muscular dystrophy and other diseases. We now evaluated LTBP4 nsSNPs in dilated cardiomyopathy, a distinct disorder associated with TGFβ signaling. We stratified based on self-identified ethnicity and found that the LTBP4 VTTT allele is associated with increased risk of dilated cardiomyopathy in European Americans extending the diseases that associate with LTBP4 genotype. However, the association of LTBP4 SNPs with dilated cardiomyopathy was not observed in African Americans. To elucidate the mechanism by which LTBP4 genotype exerts this differential effect, TGFβ’s association with LTBP4 protein was examined. LTBP4 protein with the IAAM residues bound more latent TGFβ compared to the LTBP4 VTTT protein. Together these data provide support that LTBP4 genotype exerts its effect through differential avidity for TGFβ accounting for the differences in TGFβ signaling attributed to these two alleles.