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Full-Text Articles in Chemicals and Drugs

Crystal Structure Of Apobec3a Bound To Single-Stranded Dna Reveals Structural Basis For Cytidine Deamination And Specificity, Takahide Kouno, Tania V. Silvas, Brendan J. Hilbert, Shivender Shandilya, Markus-Frederik Bohn, Brian A. Kelch, William E. Royer, Mohan Somasundaran, Nese Kurt Yilmaz, Hiroshi Matsuo, Celia A. Schiffer Jul 2017

Crystal Structure Of Apobec3a Bound To Single-Stranded Dna Reveals Structural Basis For Cytidine Deamination And Specificity, Takahide Kouno, Tania V. Silvas, Brendan J. Hilbert, Shivender Shandilya, Markus-Frederik Bohn, Brian A. Kelch, William E. Royer, Mohan Somasundaran, Nese Kurt Yilmaz, Hiroshi Matsuo, Celia A. Schiffer

Celia A. Schiffer

Nucleic acid editing enzymes are essential components of the immune system that lethally mutate viral pathogens and somatically mutate immunoglobulins, and contribute to the diversification and lethality of cancers. Among these enzymes are the seven human APOBEC3 deoxycytidine deaminases, each with unique target sequence specificity and subcellular localization. While the enzymology and biological consequences have been extensively studied, the mechanism by which APOBEC3s recognize and edit DNA remains elusive. Here we present the crystal structure of a complex of a cytidine deaminase with ssDNA bound in the active site at 2.2 A. This structure not only visualizes the active site …


Dengue Virus Ns2b/Ns3 Protease Inhibitors Exploiting The Prime Side, Kuan-Hung Lin, Akbar Ali, Linah Rusere, Djade I. Soumana, Nese Kurt Yilmaz, Celia A. Schiffer Jul 2017

Dengue Virus Ns2b/Ns3 Protease Inhibitors Exploiting The Prime Side, Kuan-Hung Lin, Akbar Ali, Linah Rusere, Djade I. Soumana, Nese Kurt Yilmaz, Celia A. Schiffer

Celia A. Schiffer

The mosquito-transmitted dengue virus (DENV) infects millions of people in tropical and subtropical regions. Maturation of DENV particles requires proper cleavage of the viral polyprotein, including processing of 8 of the 13 substrate cleavage sites by dengue virus NS2B/NS3 protease. With no available direct-acting antiviral targeting DENV, NS2/NS3 protease is a promising target for inhibitor design. Current design efforts focus on the nonprime side of the DENV protease active site, resulting in highly hydrophilic and nonspecific scaffolds. However, the prime side also significantly modulates DENV protease binding affinity, as revealed by engineering the binding loop of aprotinin, a small protein …


Inhibition Of Cholinergic Signaling Causes Apoptosis In Human Bronchioalveolar Carcinoma, Jamie K. Lau, Kathleen C. Brown, Brent A. Thornhill, Clayton M. Crabtree, Aaron M. Dom, Theodore R. Witte, W. Elaine Hardman, Christopher A. Mcnees, Cody A. Stover, A. Betts Carpenter, Haitao Luo, Yi C. Chen, Brandon S. Shiflett, Piyali Dasgupta Jun 2017

Inhibition Of Cholinergic Signaling Causes Apoptosis In Human Bronchioalveolar Carcinoma, Jamie K. Lau, Kathleen C. Brown, Brent A. Thornhill, Clayton M. Crabtree, Aaron M. Dom, Theodore R. Witte, W. Elaine Hardman, Christopher A. Mcnees, Cody A. Stover, A. Betts Carpenter, Haitao Luo, Yi C. Chen, Brandon S. Shiflett, Piyali Dasgupta

Kathleen C. Brown

Recent case-controlled clinical studies show that bronchioalveolar carcinomas (BAC) are correlated with smoking. Nicotine, the addictive component of cigarettes, accelerates cell proliferation through nicotinic acetylcholine receptors (nAChR). In this study, we show that human BACs produce acetylcholine (ACh) and contain several cholinergic factors including acetylcholinesterase (AChE), choline acetyltransferase (ChAT), choline transporter 1 (CHT1, SLC5A7), vesicular acetylcholine transporter (VAChT, SLC18A3), and nACh receptors (AChRs, CHRNAs). Nicotine increased the production of ACh in human BACs, and ACh acts as a growth factor for these cells. Nicotine-induced ACh production was mediated by α7-, α3β2-, and β3-nAChRs, ChAT and VAChT pathways. We observed that …


Interdependence Of Inhibitor Recognition In Hiv-1 Protease, Janet L. Paulsen, Florian Leidner, Debra A. Ragland, Nese Kurt Yilmaz, Celia A. Schiffer Jun 2017

Interdependence Of Inhibitor Recognition In Hiv-1 Protease, Janet L. Paulsen, Florian Leidner, Debra A. Ragland, Nese Kurt Yilmaz, Celia A. Schiffer

Celia A. Schiffer

Molecular recognition is a highly interdependent process. Subsite couplings within the active site of proteases are most often revealed through conditional amino acid preferences in substrate recognition. However, the potential effect of these couplings on inhibition and thus inhibitor design is largely unexplored. The present study examines the interdependency of subsites in HIV-1 protease using a focused library of protease inhibitors, to aid in future inhibitor design. Previously a series of darunavir (DRV) analogs was designed to systematically probe the S1' and S2' subsites. Co-crystal structures of these analogs with HIV-1 protease provide the ideal opportunity to probe subsite interdependency. …


Theaflavin-3, 3'-Digallate Decreases Human Ovarian Carcinoma Ovcar-3 Cell-Induced Angiogenesis Via Akt And Notch-1 Pathways, Not Via Mapk Pathways, Ying Gao, Gary O. Rankin, Youying Tu, Yi Charlie Chen May 2017

Theaflavin-3, 3'-Digallate Decreases Human Ovarian Carcinoma Ovcar-3 Cell-Induced Angiogenesis Via Akt And Notch-1 Pathways, Not Via Mapk Pathways, Ying Gao, Gary O. Rankin, Youying Tu, Yi Charlie Chen

Gary O. Rankin

Theaflavin-3, 3'-digallate (TF3) is a black tea polyphenol produced from polymerization and oxidization of the green tea ployphenols epicatechin gallate and (-)-epigallocatechin-3-gallate (EGCG) during fermentation of fresh tea leaves. TF3 has been reported to have anticancer properties. However, the effect of TF3 on tumor angiogenesis and the underlying mechanisms are not clear. In the present study, TF3 was verified to inhibit tumor angiogenesis. Compared with EGCG, TF3 was more potent. TF3 inhibited human ovarian carcinoma OVCAR-3 cell-induced angiogenesis in human umbilical vein endothelial cell model and in chick chorioallantoic membrane model. TF3 reduced tumor angiogenesis by downregulating HIF-1α and VEGF. …