6 research outputs found
The invertebrate Caenorhabditis elegans biosynthesizes ascorbate.
l-Ascorbate, commonly known as vitamin C, serves as an antioxidant and cofactor essential for many biological processes. Distinct ascorbate biosynthetic pathways have been established for animals and plants, but little is known about the presence or synthesis of this molecule in invertebrate species. We have investigated ascorbate metabolism in the nematode Caenorhabditis elegans, where this molecule would be expected to play roles in oxidative stress resistance and as cofactor in collagen and neurotransmitter synthesis. Using high-performance liquid chromatography and gas-chromatography mass spectrometry, we determined that ascorbate is present at low amounts in the egg stage, L1 larvae, and mixed animal populations, with the egg stage containing the highest concentrations. Incubating C. elegans with precursor molecules necessary for ascorbate synthesis in plants and animals did not significantly alter ascorbate levels. Furthermore, bioinformatic analyses did not support the presence in C. elegans of either the plant or the animal biosynthetic pathway. However, we observed the complete (13)C-labeling of ascorbate when C. elegans was grown with (13)C-labeled Escherichia coli as a food source. These results support the hypothesis that ascorbate biosynthesis in invertebrates may proceed by a novel pathway and lay the foundation for a broader understanding of its biological role
Ligand-Based Discovery of a New Scaffold for Allosteric Modulation of the μ‑Opioid Receptor
With
the hope of discovering effective analgesics with fewer side
effects, attention has recently shifted to allosteric modulators of
the opioid receptors. In the past two years, the first chemotypes
of positive or silent allosteric modulators (PAMs or SAMs, respectively)
of μ- and δ-opioid receptor types have been reported in
the literature. During a structure-guided lead optimization campaign
with μ-PAMs BMS-986121 and BMS-986122 as starting compounds,
we discovered a new chemotype that was confirmed to display μ-PAM
or μ-SAM activity depending on the specific substitutions as
assessed by endomorphin-1-stimulated β-arrestin2 recruitment
assays in Chinese Hamster Ovary (CHO)-μ PathHunter cells. The
most active μ-PAM of this series was analyzed further in competition
binding and G-protein activation assays to understand its effects
on ligand binding and to investigate the nature of its probe dependence
The invertebrate Caenorhabditis elegans biosynthesizes ascorbate
L-ascorbate, commonly known as vitamin C, serves as an antioxidant and cofactor essential for many biological processes. Distinct ascorbate biosynthetic pathways have been established for animals and plants, but little is known about the presence or synthesis of this molecule in invertebrate species. We have investigated ascorbate metabolism in the nematode Caenorhabditis elegans, where this molecule would be expected to play roles in oxidative stress resistance and as cofactor in collagen and neurotransmitter synthesis. Using high-performance liquid chromatography and gas-chromatography mass spectrometry, we determined that ascorbate is present at low amounts in the egg stage, L1 larvae, and mixed animal populations, with the egg stage containing the highest concentrations. Incubating C. elegans with precursor molecules necessary for ascorbate synthesis in plants and animals did not significantly alter ascorbate levels. Furthermore, bioinformatic analyses did not support the presence in C. elegans of either the plant or the animal biosynthetic pathway. However, we observed the complete (13)C-labeling of ascorbate when C. elegans was grown with (13)C-labeled Escherichia coli as a food source. These results support the hypothesis that ascorbate biosynthesis in invertebrates may proceed by a novel pathway and lay the foundation for a broader understanding of its biological role