Triosephosphate isomerase (TPI) performs the 5th step in glycolysis, operates near the limit of diffusion, and is involved in "moonlighting" functions. Its dimer was found singly phosphorylated at Ser20 (pSer20) in human cells, with this post-translational modification (PTM) showing context-dependent stoichiometry and loss under oxidative stress. We generated synthetic pSer20 proteoforms using cell-free protein synthesis that showed enhanced TPI activity by 4-fold relative to unmodified TPI.
View Article and Find Full Text PDFRationale: Patients with cancer have elevated risk of both venous thromboembolism and bleeding compared with patients without cancer due to cancer- and patient-specific factors. Balancing the increased and competing risks of clotting and bleeding in these patients can be difficult because management of cancer-associated thrombosis requires anticoagulation despite its known increased risks for bleeding. The adjustment of blood transfusion or cessation of anticoagulants can be a challenge in surgical diagnosis or treatment of cancer patients with such an imbalanced coagulate status.
View Article and Find Full Text PDFBackground: Ischemia/reperfusion (IR) injury is 1 of the major problems in liver surgery. This study aims to evaluate the histologic and biochemical effects of dexmedetomidine on ischemia/reperfusion injury in the liver of rats.
Methods: Twenty-two Sprague-Dawley male rats were separated into 3 groups: group sham, IR (IR injury), and IR-D (IR with dexmedetomidine).
Aerobic methane oxidation is catalyzed by particulate methane monooxygenase (pMMO), a copper-dependent, membrane metalloenzyme composed of subunits PmoA, PmoB, and PmoC. Characterization of the copper active site has been limited by challenges in spectroscopic analysis stemming from the presence of multiple copper binding sites, effects of detergent solubilization on activity and crystal structures, and the lack of a heterologous expression system. Here we utilize nanodiscs coupled with native top-down mass spectrometry (nTDMS) to determine the copper stoichiometry in each pMMO subunit and to detect post-translational modifications (PTMs).
View Article and Find Full Text PDFBackground: There have been reports of neurolytic transversus abdominis plane (TAP) block using different agents such as alcohol or phenol for the treatment of chronic abdominal pain caused by malignant abdominal wall invasion. However, to date, there have been no reports on neurolytic abdominal wall blocks for pain with non-cancer-related origin in cancer patients.
Case: We performed subcostal TAP neurolysis using ethanol in a patient with esophageal cancer with constant pain at the site of gastrostomy.
In methylotrophic bacteria, which use one-carbon (C1) compounds as a carbon source, methanol is oxidized by pyrroloquinoline quinone (PQQ)-dependent methanol dehydrogenase (MDH) enzymes. Methylotrophic genomes generally encode two distinct MDHs, MxaF and XoxF. MxaF is a well-studied, calcium-dependent heterotetrameric enzyme whereas XoxF is a lanthanide-dependent homodimer.
View Article and Find Full Text PDFMethods Enzymol
May 2019
Methanotrophic bacteria utilize methane as their sole carbon and energy source. Studies of the model Type II methanotroph Methylosinus trichosporium OB3b have provided insight into multiple aspects of methanotrophy, including methane assimilation, copper accumulation, and metal-dependent gene expression. Development of genetic tools for chromosomal editing was crucial for advancing these studies.
View Article and Find Full Text PDFParticulate methane monooxygenase (pMMO) is a copper-dependent integral membrane metalloenzyme that converts methane to methanol in methanotrophic bacteria. Studies of isolated pMMO have been hindered by loss of enzymatic activity upon its removal from the native membrane. To characterize pMMO in a membrane-like environment, we reconstituted pMMOs from () (Bath) and () 20Z into bicelles.
View Article and Find Full Text PDFMetal homeostasis poses a major challenge to microbes, which must acquire scarce elements for core metabolic processes. Methanobactin, an extensively modified copper-chelating peptide, was one of the earliest natural products shown to enable microbial acquisition of a metal other than iron. We describe the core biosynthetic machinery responsible for the characteristic posttranslational modifications that grant methanobactin its specificity and affinity for copper.
View Article and Find Full Text PDFMethanotrophic bacteria use methane, a potent greenhouse gas, as their primary source of carbon and energy. The first step in methane metabolism is its oxidation to methanol. In almost all methanotrophs, this chemically challenging reaction is catalyzed by particulate methane monooxygenase (pMMO), a copper-dependent integral membrane enzyme.
View Article and Find Full Text PDFIndustrial biotechnology provides an efficient, sustainable solution for chemical production. However, designing biochemical pathways based solely on known reactions does not exploit its full potential. Enzymes are known to accept non-native substrates, which may allow novel, advantageous reactions.
View Article and Find Full Text PDFPhotosynthetic conversion of CO2 to chemicals using cyanobacteria is an attractive approach for direct recycling of CO2 to useful products. 3-Hydroxypropionic acid (3 HP) is a valuable chemical for the synthesis of polymers and serves as a precursor to many other chemicals such as acrylic acid. 3 HP is naturally produced through glycerol metabolism.
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