Human ISPD Is a Cytidyltransferase Required for Dystroglycan O-Mannosylation
Chem Biol. 2015 Dec 17;22(12):1643-52. doi: 10.1016/j.chembiol.2015.10.014. Epub 2015 Dec 10.ABSTRACTA unique, unsolved O-mannosyl glycan on α-dystroglycan is essential for its interaction with protein ligands in the extracellular matrix. Defective O-mannosylation leads to a group of muscular dystrophies, called dystroglycanopathies. Mutations in isoprenoid synthase domain containing (ISPD) represent the second most common cause of these disorders, however, its molecular function remains uncharacterized. The human ISPD (hISPD) crystal structure showed a canonical N-terminal cytidyltransferase domain linked to a C-terminal...
Source: Chemistry and Biology - December 22, 2015 Category: Chemistry Authors: Moniek Riemersma D Sean Froese Walinka van Tol Udo F Engelke Jolanta Kopec Monique van Scherpenzeel Angel Ashikov Tobias Krojer Frank von Delft Marco Tessari Anna Buczkowska Ewa Swiezewska Lucas T Jae Thijn R Brummelkamp Hiroshi Manya Tamao Endo Hans van Source Type: research

Vitamin C as Cancer Destroyer, Investigating Sulfhydration, and the Variability in CFTR Interactome
Chem Biol. 2015 Dec 17;22(12):1575-6. doi: 10.1016/j.chembiol.2015.12.002.ABSTRACTEach month, Chemistry & Biology Select highlights a selection of research reports from the recent literature. These highlights are a snapshot of interesting research done across the field of chemical biology. Our December 2015 selection includes an insight into how vitamin C destroys cancer cells, a new method that makes possible the investigatation of sulfhydration, and the mapping of the CFTR interactome and how it depends on the environmental conditions and differs between wild-type and disease-causing mutant. PMID:26687480 | DOI:10.10...
Source: Chemistry and Biology - December 22, 2015 Category: Chemistry Source Type: research

Unraveling the B.  pseudomallei Heptokinase WcbL: From Structure to Drug Discovery
We report that WcbL operates through a sequential ordered Bi-Bi mechanism, loading the heptose first and then ATP. We show that dimeric WcbL binds ATP anti-cooperatively in the absence of heptose, and cooperatively in its presence. Modeling of WcbL suggests that heptose binding causes an elegant switch in the hydrogen-bonding network, facilitating the binding of a second ATP molecule. Finally, we screened a library of drug-like fragments, identifying hits that potently inhibit WcbL. Our results provide a novel mechanism for control of substrate binding and emphasize WcbL as an attractive anti-microbial target for Gram-nega...
Source: Chemistry and Biology - December 22, 2015 Category: Chemistry Authors: Mirella Vivoli Michail N Isupov Rebecca Nicholas Andrew Hill Andrew E Scott Paul Kosma Joann L Prior Nicholas J Harmer Source Type: research

Synthetic Peptides as cGMP-Independent Activators of cGMP-Dependent Protein Kinase I α
In this study, a set of synthetic peptides (S-tides), derived from this helix, was found to bind to and activate PKG Iα in a cyclic guanosine monophosphate (cGMP)-independent manner. The most potent S-tide derivative (S1.5) increased the open probability of the potassium channel KCa1.1 to levels equivalent to saturating cGMP. Introduction of S1.5 to smooth muscle cells in isolated, endothelium-denuded cerebral arteries through a modified reversible permeabilization procedure inhibited myogenic constriction. In contrast, in endothelium-intact vessels S1.5 had no effect on myogenic tone. This suggests that PKG Iα activatio...
Source: Chemistry and Biology - December 22, 2015 Category: Chemistry Authors: Thomas M Moon Nathan R Tykocki Jessica L Sheehe Brent W Osborne Werner Tegge Joseph E Brayden Wolfgang R Dostmann Source Type: research

Differential Regulation of Specific Sphingolipids in Colon Cancer Cells during Staurosporine-Induced Apoptosis
Chem Biol. 2015 Dec 17;22(12):1662-70. doi: 10.1016/j.chembiol.2015.11.004.ABSTRACTApoptosis is accompanied by distinct morphological changes at the plasma and organelle membrane level. Involvement of certain lipids in apoptosis has been established; however, we have limited understanding of the specific lipid structures that participate in this process. We used untargeted comparative lipidomics to study the changes in lipid composition during staurosporine-induced apoptosis in HCT-116. Our results revealed that ceramides, dihydroceramides, and sphingomyelins, with defined acyl chains, constitute the majority of changes in...
Source: Chemistry and Biology - December 22, 2015 Category: Chemistry Authors: Virginia del Solar Darleny Y Lizardo Nasi Li Jerod J Hurst Christopher J Brais G Ekin Atilla-Gokcumen Source Type: research

DIVERSE System: De Novo Creation of Peptide Tags for Non-enzymatic Covalent Labeling by In  Vitro Evolution for Protein Imaging Inside Living Cells
Chem Biol. 2015 Dec 17;22(12):1671-9. doi: 10.1016/j.chembiol.2015.10.016.ABSTRACTPolypeptide-tag/small-molecule pairs for specific cellular protein labeling are useful for visualizing cellular proteins and controlling their activity. Here, we report the development of an in vitro evolution-based (poly)peptide tag identification system named the DIVERSE (Directed In Vitro Evolution of Reactive peptide tags via Sequential Enrichment) system. In this system, an extremely diverse (10(14)) library of peptide tags, displayed by covalent attachment to their encoding cDNAs, is continuously prepared from the DNA library in a one-p...
Source: Chemistry and Biology - December 22, 2015 Category: Chemistry Authors: Takashi Kawakami Koji Ogawa Naoki Goshima Tohru Natsume Source Type: research

Human ISPD Is a Cytidyltransferase Required for Dystroglycan O-Mannosylation
Chem Biol. 2015 Dec 17;22(12):1643-52. doi: 10.1016/j.chembiol.2015.10.014. Epub 2015 Dec 10.ABSTRACTA unique, unsolved O-mannosyl glycan on α-dystroglycan is essential for its interaction with protein ligands in the extracellular matrix. Defective O-mannosylation leads to a group of muscular dystrophies, called dystroglycanopathies. Mutations in isoprenoid synthase domain containing (ISPD) represent the second most common cause of these disorders, however, its molecular function remains uncharacterized. The human ISPD (hISPD) crystal structure showed a canonical N-terminal cytidyltransferase domain linked to a C-terminal...
Source: Chemistry and Biology - December 22, 2015 Category: Chemistry Authors: Moniek Riemersma D Sean Froese Walinka van Tol Udo F Engelke Jolanta Kopec Monique van Scherpenzeel Angel Ashikov Tobias Krojer Frank von Delft Marco Tessari Anna Buczkowska Ewa Swiezewska Lucas T Jae Thijn R Brummelkamp Hiroshi Manya Tamao Endo Hans van Source Type: research

Vitamin C as Cancer Destroyer, Investigating Sulfhydration, and the Variability in CFTR Interactome
Chem Biol. 2015 Dec 17;22(12):1575-6. doi: 10.1016/j.chembiol.2015.12.002.ABSTRACTEach month, Chemistry & Biology Select highlights a selection of research reports from the recent literature. These highlights are a snapshot of interesting research done across the field of chemical biology. Our December 2015 selection includes an insight into how vitamin C destroys cancer cells, a new method that makes possible the investigatation of sulfhydration, and the mapping of the CFTR interactome and how it depends on the environmental conditions and differs between wild-type and disease-causing mutant. PMID:26687480 | DOI:10.10...
Source: Chemistry and Biology - December 22, 2015 Category: Chemistry Source Type: research

Unraveling the B.  pseudomallei Heptokinase WcbL: From Structure to Drug Discovery
We report that WcbL operates through a sequential ordered Bi-Bi mechanism, loading the heptose first and then ATP. We show that dimeric WcbL binds ATP anti-cooperatively in the absence of heptose, and cooperatively in its presence. Modeling of WcbL suggests that heptose binding causes an elegant switch in the hydrogen-bonding network, facilitating the binding of a second ATP molecule. Finally, we screened a library of drug-like fragments, identifying hits that potently inhibit WcbL. Our results provide a novel mechanism for control of substrate binding and emphasize WcbL as an attractive anti-microbial target for Gram-nega...
Source: Chemistry and Biology - December 22, 2015 Category: Chemistry Authors: Mirella Vivoli Michail N Isupov Rebecca Nicholas Andrew Hill Andrew E Scott Paul Kosma Joann L Prior Nicholas J Harmer Source Type: research

Synthetic Peptides as cGMP-Independent Activators of cGMP-Dependent Protein Kinase I α
In this study, a set of synthetic peptides (S-tides), derived from this helix, was found to bind to and activate PKG Iα in a cyclic guanosine monophosphate (cGMP)-independent manner. The most potent S-tide derivative (S1.5) increased the open probability of the potassium channel KCa1.1 to levels equivalent to saturating cGMP. Introduction of S1.5 to smooth muscle cells in isolated, endothelium-denuded cerebral arteries through a modified reversible permeabilization procedure inhibited myogenic constriction. In contrast, in endothelium-intact vessels S1.5 had no effect on myogenic tone. This suggests that PKG Iα activatio...
Source: Chemistry and Biology - December 22, 2015 Category: Chemistry Authors: Thomas M Moon Nathan R Tykocki Jessica L Sheehe Brent W Osborne Werner Tegge Joseph E Brayden Wolfgang R Dostmann Source Type: research

Differential Regulation of Specific Sphingolipids in Colon Cancer Cells during Staurosporine-Induced Apoptosis
Chem Biol. 2015 Dec 17;22(12):1662-70. doi: 10.1016/j.chembiol.2015.11.004.ABSTRACTApoptosis is accompanied by distinct morphological changes at the plasma and organelle membrane level. Involvement of certain lipids in apoptosis has been established; however, we have limited understanding of the specific lipid structures that participate in this process. We used untargeted comparative lipidomics to study the changes in lipid composition during staurosporine-induced apoptosis in HCT-116. Our results revealed that ceramides, dihydroceramides, and sphingomyelins, with defined acyl chains, constitute the majority of changes in...
Source: Chemistry and Biology - December 22, 2015 Category: Chemistry Authors: Virginia del Solar Darleny Y Lizardo Nasi Li Jerod J Hurst Christopher J Brais G Ekin Atilla-Gokcumen Source Type: research

DIVERSE System: De Novo Creation of Peptide Tags for Non-enzymatic Covalent Labeling by In  Vitro Evolution for Protein Imaging Inside Living Cells
Chem Biol. 2015 Dec 17;22(12):1671-9. doi: 10.1016/j.chembiol.2015.10.016.ABSTRACTPolypeptide-tag/small-molecule pairs for specific cellular protein labeling are useful for visualizing cellular proteins and controlling their activity. Here, we report the development of an in vitro evolution-based (poly)peptide tag identification system named the DIVERSE (Directed In Vitro Evolution of Reactive peptide tags via Sequential Enrichment) system. In this system, an extremely diverse (10(14)) library of peptide tags, displayed by covalent attachment to their encoding cDNAs, is continuously prepared from the DNA library in a one-p...
Source: Chemistry and Biology - December 22, 2015 Category: Chemistry Authors: Takashi Kawakami Koji Ogawa Naoki Goshima Tohru Natsume Source Type: research

Human ISPD Is a Cytidyltransferase Required for Dystroglycan O-Mannosylation
Chem Biol. 2015 Dec 17;22(12):1643-52. doi: 10.1016/j.chembiol.2015.10.014. Epub 2015 Dec 10.ABSTRACTA unique, unsolved O-mannosyl glycan on α-dystroglycan is essential for its interaction with protein ligands in the extracellular matrix. Defective O-mannosylation leads to a group of muscular dystrophies, called dystroglycanopathies. Mutations in isoprenoid synthase domain containing (ISPD) represent the second most common cause of these disorders, however, its molecular function remains uncharacterized. The human ISPD (hISPD) crystal structure showed a canonical N-terminal cytidyltransferase domain linked to a C-terminal...
Source: Chemistry and Biology - December 22, 2015 Category: Chemistry Authors: Moniek Riemersma D Sean Froese Walinka van Tol Udo F Engelke Jolanta Kopec Monique van Scherpenzeel Angel Ashikov Tobias Krojer Frank von Delft Marco Tessari Anna Buczkowska Ewa Swiezewska Lucas T Jae Thijn R Brummelkamp Hiroshi Manya Tamao Endo Hans van Source Type: research

Vitamin C as Cancer Destroyer, Investigating Sulfhydration, and the Variability in CFTR Interactome
Chem Biol. 2015 Dec 17;22(12):1575-6. doi: 10.1016/j.chembiol.2015.12.002.ABSTRACTEach month, Chemistry & Biology Select highlights a selection of research reports from the recent literature. These highlights are a snapshot of interesting research done across the field of chemical biology. Our December 2015 selection includes an insight into how vitamin C destroys cancer cells, a new method that makes possible the investigatation of sulfhydration, and the mapping of the CFTR interactome and how it depends on the environmental conditions and differs between wild-type and disease-causing mutant. PMID:26687480 | DOI:10.10...
Source: Chemistry and Biology - December 22, 2015 Category: Chemistry Source Type: research

Unraveling the B.  pseudomallei Heptokinase WcbL: From Structure to Drug Discovery
We report that WcbL operates through a sequential ordered Bi-Bi mechanism, loading the heptose first and then ATP. We show that dimeric WcbL binds ATP anti-cooperatively in the absence of heptose, and cooperatively in its presence. Modeling of WcbL suggests that heptose binding causes an elegant switch in the hydrogen-bonding network, facilitating the binding of a second ATP molecule. Finally, we screened a library of drug-like fragments, identifying hits that potently inhibit WcbL. Our results provide a novel mechanism for control of substrate binding and emphasize WcbL as an attractive anti-microbial target for Gram-nega...
Source: Chemistry and Biology - December 22, 2015 Category: Chemistry Authors: Mirella Vivoli Michail N Isupov Rebecca Nicholas Andrew Hill Andrew E Scott Paul Kosma Joann L Prior Nicholas J Harmer Source Type: research