keyword
https://read.qxmd.com/read/37716155/cloning-and-deorphanization-of-three-inotocin-insect-oxytocin-vasopressin-like-receptors-and-their-ligand-from-the-tick-ixodes-scapularis
#21
JOURNAL ARTICLE
Frank Hauser, Tara Al-Ribaty, Marisa Stebegg, Gedske Thygesen, Cornelis J P Grimmelikhuijzen
Many insects produce the cyclic neuropeptide inotocin (CLITNCPRGamide), which is the insect orthologue of the mammalian neuropeptides oxytocin and vasopressin. These insects also have one inotocin G protein-coupled receptor (GPCR), which is the orthologue of the mammalian oxytocin and vasopressin receptors. The tick Ixodes scapularis belongs to the subphylum Chelicerata, an arthropod taxon different from insects, to which also spiders, scorpions, and mites belong. I. scapularis is an ectoparasite and a health risk for humans, because it transfers pathogenic microorganisms to its human host during a blood meal, thereby causing serious neurological diseases, among them Lyme disease and tick-borne encephalitis (TBE)...
September 9, 2023: Biochemical and Biophysical Research Communications
https://read.qxmd.com/read/37594412/luminescent-iridium-iii-porphyrin-complexes-as-near-infrared-emissive-biological-probes
#22
JOURNAL ARTICLE
Lijuan Hua, Kenneth Yin Zhang, Hua-Wei Liu, Kin-Shing Chan, Kenneth Kam-Wing Lo
We report herein the design, synthesis and characterisation of a series of luminescent iridium(III) porphyrin complexes [Ir(ttp)(CH2 CH2 OH)] (H2 ttp = 5,10,15,20-tetra-4-tolylporphyrin) (1), [Ir(tpp-Ph-NO2 )(CO)Cl] (H2 tpp-Ph-NO2 = 5-(4-((4-nitrophenoxy)carbonyloxymethyl)phenyl)-10,15,20-triphenylporphyrin) (2), [Ir(tpp-COOMe)(Py)2 ](Cl) (H2 tpp-COOMe = 5-(4-methoxycarbonylphenyl)-10,15,20-triphenylporphyrin; Py = pyridine) (3) and [Ir(tpp-COOH)(Py)2 ](Cl) (H2 tpp-COOH = 5-(4-carboxylphenyl)-10,15,20-triphenylporphyrin) (4)...
August 18, 2023: Dalton Transactions: An International Journal of Inorganic Chemistry
https://read.qxmd.com/read/37589157/hdx-ms-reveals-substrate-dependent-localized-ex1-conformational-dynamics-in-the-retaining-gt-b-glycosyltransferase-msha
#23
JOURNAL ARTICLE
Ramesh Karki, Jacquelyn T Hennek, Wen Chen, Patrick A Frantom
Glycosyltransferases (GTs) are well-characterized with respect to static 3D structures and molecular dynamics simulations, but there is a lack of reports on in-solution dynamics on time scales relevant to turnover. Here, backbone amide hydrogen/deuterium exchange followed by mass spectrometry (HDX-MS) was used to investigate the in-solution dynamics of the model retaining GT MshA from Corynebacterium glutamicum (CgMshA). CgMshA has a GT-B fold and catalyzes the transfer of N -acetyl-glucosamine (GlcNAc) from UDP-GlcNAc to l- myo -inositol-1-phosphate in the first step in mycothiol biosynthesis...
August 17, 2023: Biochemistry
https://read.qxmd.com/read/37499370/electron-withdrawing-group-dependent-substrate-inhibition-of-an-%C3%AE-ketoamide-reductase-from-saccharomyces-cerevisiae
#24
JOURNAL ARTICLE
Zarina Akbary, Honglin Yu, Ivelisse Lorenzo, Karyme Paez, Narisa Diana Lee, Kayla DeBeVoise, Joel Moses, Nathaniel Sanders, Neal Connors, Adam Cassano
Aldo-keto reductases remain enzymes of interest in biocatalysis due to their ability to reduce carbonyls to alcohols stereospecifically. Based on genomic sequence, we identified aldo-keto reductases of a S. cerevisiae strain extracted from an ancient amber sample. One of the putative enzymes, AKR 163, displays 99% identity with α-amide ketoreductases from the S288C and YJM248 S. cerevisiae strains, which have been investigated for biocatalytic applications. To further investigate AKR 163, we successfully cloned, expressed in E...
July 15, 2023: Biochemical and Biophysical Research Communications
https://read.qxmd.com/read/37457366/synthesis-molecular-structure-and-urease-inhibitory-activity-of-novel-bis-schiff-bases-of-benzyl-phenyl-ketone-a-combined-theoretical-and-experimental-approach
#25
JOURNAL ARTICLE
Rashid Ahmad, Momin Khan, Aftab Alam, Ahmed A Elhenawy, Abdul Qadeer, Abdullah F AlAsmari, Metab Alharbi, Fawaz Alasmari, Manzoor Ahmad
BACKGROUND: Urease belongs to the family of amid hydrolases with two nickel atoms in their core structure. On the basis of literature survey, this research work is mainly focused on the study of bis -Schiff base derivatives of benzyl phenyl ketone nucleus. OBJECTIVE: Synthesis of benzyl phenyl ketone based bis -Schiff bases in search of potent urease inhibitors. METHOD: In the current work, bis -Schiff bases were synthesized through two steps reaction by reacting benzyl phenyl ketone with excess of hydrazine hydrate in ethanol solvent in the first step to get the desired hydrazone...
August 2023: Saudi Pharmaceutical Journal: SPJ: the Official Publication of the Saudi Pharmaceutical Society
https://read.qxmd.com/read/37399384/ecoevolutionary-processes-structure-milk-microbiomes-across-the-mammalian-tree-of-life
#26
JOURNAL ARTICLE
Mia M Keady, Randall R Jimenez, Morgan Bragg, Jenna C P Wagner, Sally L Bornbusch, Michael L Power, Carly R Muletz-Wolz
Milk production is an ancient adaptation that unites all mammals. Milk contains a microbiome that can contribute to offspring health and microbial-immunological development. We generated a comprehensive milk microbiome dataset (16S rRNA gene) for the class Mammalia, representing 47 species from all placental superorders, to determine processes structuring milk microbiomes. We show that across Mammalia, milk exposes offspring to maternal bacterial and archaeal symbionts throughout lactation. Deterministic processes of environmental selection accounted for 20% of milk microbiome assembly processes; milk microbiomes were similar from mammals with the same host superorder (Afrotheria, Laurasiathera, Euarchontoglires, and Xenarthra: 6%), environment (marine captive, marine wild, terrestrial captive, and terrestrial wild: 6%), diet (carnivore, omnivore, herbivore, and insectivore: 5%), and milk nutrient content (sugar, fat, and protein: 3%)...
July 11, 2023: Proceedings of the National Academy of Sciences of the United States of America
https://read.qxmd.com/read/37398099/a-subtle-structural-modification-of-a-synthetic-cannabinoid-receptor-agonist-drastically-increases-its-efficacy-at-the-cb1-receptor
#27
Hideaki Yano, Rezvan Chitsazi, Christopher Lucaj, Phuong Tran, Alexander F Hoffman, Michael H Baumann, Carl R Lupica, Lei Shi
The emergence of synthetic cannabinoid receptor agonists (SCRAs) as illicit psychoactive substances has posed considerable public health risks that include fatalities. Many SCRAs exhibit much higher efficacy and potency, compared with the phytocannabinoid Δ 9 -tetrahydrocannabinol (THC), at the cannabinoid receptor 1 (CB1R), a G protein-coupled receptor involved in modulating neurotransmitter release. In this study, we investigated structure activity relationships (SAR) of aminoalkylindole SCRAs at CB1Rs, focusing on 5F-pentylindoles containing an amide linker attached to different head moieties...
June 12, 2023: bioRxiv
https://read.qxmd.com/read/37321378/cest2022-amide-proton-transfer-weighted-mri-improves-the-diagnostic-performance-of-multiparametric-non-contrast-enhanced-mri-techniques-in-patients-with-post-treatment-high-grade-gliomas
#28
JOURNAL ARTICLE
Qianqi Huang, Jingpu Wu, Nhat Le, Yiqing Shen, Pengfei Guo, Karisa C Schreck, David Kamson, Lindsay Blair, Hye Young Heo, Xu Li, Wenbo Li, Haris L Sair, Jaishri O Blakeley, John Laterra, Matthias Holdhoff, Stuart A Grossman, Debraj Mukherjee, Chetan Bettegowda, Peter van Zijl, Jinyuan Zhou, Shanshan Jiang
New or enlarged lesions in malignant gliomas after surgery and chemoradiation can be associated with tumor recurrence or treatment effect. Due to similar radiographic characteristics, conventional-and even some advanced MRI techniques-are limited in distinguishing these two pathologies. Amide proton transfer-weighted (APTw) MRI, a protein-based molecular imaging technique that does not require the administration of any exogenous contrast agent, was recently introduced into the clinical setting. In this study, we evaluated and compared the diagnostic performances of APTw MRI with several non-contrast-enhanced MRI sequences, such as diffusion-weighted imaging, susceptibility-weighted imaging, and pseudo-continuous arterial spin labeling...
June 13, 2023: Magnetic Resonance Imaging
https://read.qxmd.com/read/37300639/studying-micro-to-millisecond-protein-dynamics-using-simple-amide-15-n-cest-experiments-supplemented-with-major-state-r-2-and-visible-peak-position-constraints
#29
JOURNAL ARTICLE
Nihar Pradeep Khandave, Ashok Sekhar, Pramodh Vallurupalli
Over the last decade amide 15 N CEST experiments have emerged as a popular tool to study protein dynamics that involves exchange between a 'visible' major state and sparsely populated 'invisible' minor states. Although initially introduced to study exchange between states that are in slow exchange with each other (typical exchange rates of, 10 to 400 s-1 ), they are now used to study interconversion between states on the intermediate to fast exchange timescale while still using low to moderate (5 to 350 Hz) 'saturating' B1 fields...
June 10, 2023: Journal of Biomolecular NMR
https://read.qxmd.com/read/37267707/redistribution-of-perfluorooctanoic-acid-in-sludge-after-thermal-hydrolysis-location-of-protein-plays-a-major-role
#30
JOURNAL ARTICLE
Wangwang Yan, Mengsha Song, Yan Zhou
Perfluorinated compounds (PFCs) are a group of bio-recalcitrant pollutants that remain in waste activated sludge and may subsequently be transferred with sludge to thermal hydrolysis pretreatment (THP) process. Instead of reduction, it is observed previously that the concentration of free PFCs elevated after THP. By employing perfluorooctanoic acid (PFOA) as a representative, this study developed a hierarchical scheme to pinpoint the key factors that contribute to free PFOA elevation from the complex sludge transformations...
May 27, 2023: Water Research
https://read.qxmd.com/read/37218930/raft-polymer-antibody-conjugation-squaramide-ester-chemistry-leads-to-conjugates-with-a-therapeutic-anti-egfr-antibody-with-full-retention-of-activity-and-increased-tumor-uptake-in-vivo
#31
JOURNAL ARTICLE
Aditya Ardana, Saikat Ghosh, Pie Huda, Nicholas L Fletcher, Kristofer J Thurecht, Charlotte C Williams
Covalent conjugation of a biologically stable polymer to a therapeutic protein, e.g., an antibody, holds many benefits such as prolonged plasma exposure of the protein and improved tumor uptake. Generation of defined conjugates is advantageous in many applications, and a range of site-selective conjugation methods have been reported. Many current coupling methods lead to dispersity in coupling efficiencies with subsequent conjugates of less-well-defined structure, which impacts reproducibility of manufacture and ultimately may impact successful translation to treat or image diseases...
May 23, 2023: Molecular Pharmaceutics
https://read.qxmd.com/read/37163574/detecting-interplay-of-chirality-water-and-interfaces-for-elucidating-biological-functions
#32
JOURNAL ARTICLE
Elsa C Y Yan, Ethan A Perets, Daniel Konstantinovsky, Sharon Hammes-Schiffer
ConspectusChemists have long been fascinated by chirality, water, and interfaces, making tremendous progress in each research area. However, the chemistry emerging from the interplay of chirality, water, and interfaces has been difficult to study due to technical challenges, creating a barrier to elucidating biological functions at interfaces. Most biopolymers (proteins, DNA, and RNA) fold into macroscopic chiral structures to perform biological functions. Their folding requires water, but water behaves differently at interfaces where the bulk water hydrogen-bonding network terminates...
May 10, 2023: Accounts of Chemical Research
https://read.qxmd.com/read/37156101/reason-for-the-increased-electroactivity-of-extracellular-polymeric-substances-with-electrical-stimulation-structural-change-of-%C3%AE-helix-peptide-of-protein
#33
JOURNAL ARTICLE
Zhihao Jiang, Qilin Yu, Zhiqiang Zhao, Xingyuan Song, Yaobin Zhang
Electroactivity is an important parameter to assess the ability of the extracellular polymeric substance (EPS) of microorganisms to participate in extracellular respiration. Many reports have found that the electroactivity of microbial sludge could be enhanced with electrical stimulation, but the reason remains unclear. The results of this study showed that the current generation of the three microbial electrolysis cells increased by 1.27-1.76 times during 49 days of electrical stimulation, but the typical electroactive microorganisms were not enriched...
April 28, 2023: Water Research
https://read.qxmd.com/read/37134298/computational-mechanistic-investigations-of-biocatalytic-nitrenoid-c-h-functionalizations-via-engineered-heme-proteins
#34
JOURNAL ARTICLE
Yong Zhang, Jia-Min Chu
Engineered heme proteins were developed to possess numerous excellent biocatalytic nitrenoid C-H functionalizations. Computational approaches such as density functional theory (DFT), hybrid quantum mechanics/molecular mechanics (QM/MM), and molecular dynamics (MD) calculations were employed to help understand some important mechanistic aspects of these heme nitrene transfer reactions. This review summarizes advances of computational reaction pathway results of these biocatalytic intramolecular and intermolecular C-H aminations/amidations, focusing on mechanistic origins of reactivity, regioselectivity, enantioselectivity, diastereoselectivity as well as effects of substrate substituent, axial ligand, metal center, and protein environment...
May 3, 2023: Chembiochem: a European Journal of Chemical Biology
https://read.qxmd.com/read/37102196/modifying-enzymatic-substrate-binding-within-a-metal-organic-capsule-for-supramolecular-catalysis
#35
JOURNAL ARTICLE
Yang Yang, Xu Jing, Youpeng Shi, Yuchen Wu, Chunying Duan
Supramolecular catalysis is established to modify reaction kinetics by substrate encapsulation, but manipulating the thermodynamics of electron-transfer reactions remains unexplored. Herein, we reported a new microenvironment-shielding approach to induce an anodic shift in the redox potentials of hydrazine substrates, reminiscent of the enzymatic activation for N-N bond cleavage within a metal-organic capsule H1 . Equipped with the catalytic active cobalt sites and substrate-binding amide groups, H1 encapsulated the hydrazines to form the substrate-involving clathration intermediate, triggering the catalytic reduction N-N bond cleavage when electrons were acquired from the electron donors...
April 26, 2023: Journal of the American Chemical Society
https://read.qxmd.com/read/37083399/mechanism-of-asparagine-mediated-proton-transfer-in-photosynthetic-reaction-centers
#36
JOURNAL ARTICLE
Yu Sugo, Hiroshi Ishikita
In photosynthetic reaction centers from purple bacteria (PbRCs), light-induced charge separation leads to the reduction of the terminal electron acceptor quinone, QB . The reduction of QB to QB •- is followed by protonation via Asp-L213 and Ser-L223 in PbRC from Rhodobacter sphaeroides . However, Asp-L213 is replaced with nontitratable Asn-L222 and Asn-L213 in PbRCs from Thermochromatium tepidum and Blastochloris viridis , respectively. Here, we investigated the energetics of proton transfer along the asparagine-involved H-bond network using a quantum mechanical/molecular mechanical approach...
April 21, 2023: Biochemistry
https://read.qxmd.com/read/37047596/quantitative-susceptibility-mapping-and-amide-proton-transfer-chemical-exchange-saturation-transfer-for-the-evaluation-of-intracerebral-hemorrhage-model
#37
JOURNAL ARTICLE
Reika Sawaya, Junpei Ueda, Shigeyoshi Saito
This study aimed to evaluate an intracerebral hemorrhage (ICH) model using quantitative susceptibility mapping (QSM) and chemical exchange saturation transfer (CEST) with preclinical 7T-magnetic resonance imaging (MRI) and determine the potential of amide proton transfer-CEST (APT-CEST) for use as a biomarker for the early detection of ICH. Six Wistar male rats underwent MRI, and another six underwent histopathological examinations on postoperative days 0, 3, and 7. The ICH model was created by injecting bacterial collagenase into the right hemisphere of the brain...
April 1, 2023: International Journal of Molecular Sciences
https://read.qxmd.com/read/37042470/non-enzymatic-protein-templates-amide-bond-formation-and-provides-catalytic-turnover
#38
JOURNAL ARTICLE
Nicolas Brauckhoff, Laura Fang, Anissa Haim, Tom N Grossmann
The spatial alignment of functional groups is a central aspect of most catalytic processes. Protein scaffolds with their exceptional molecular recognition properties have evolved into powerful biological catalysts. However, the rational design of artificial enzymes starting from non-catalytic protein domains proved challenging. Herein, we report the use of a non-enzymatic protein as template for amide bond formation. Starting from a protein adaptor domain capable of simultaneously binding to two peptide ligands, we designed a catalytic transfer reaction based on the native chemical ligation...
April 12, 2023: Chemical Communications: Chem Comm
https://read.qxmd.com/read/37026369/formation-and-loading-of-a-2s-2-ethylmalonamyl%C3%A2-starter-unit-in-the-assembly-line-of-polyketide-nonribosomal-peptide-hybrid-sanglifehrin-a
#39
JOURNAL ARTICLE
Zhijun Tang, Bo Pang, Chang Liu, Shengjie Guo, Xudong Qu, Wen Liu
Sanglifehrin A (SFA) is a spirolactam-conjugated, 22-membered macrolide with remarkable immunosuppressive and antiviral activities. This macrolide is a result of a hybrid polyketide synthase (PKS)-nonribosomal peptide synthetase (NRPS) assembly line that utilizes (2S)-2-ethylmalonamyl as a starter unit. Here, we report that the formation and loading of this starter unit in the SFA assembly line involve two unusual enzymatic reactions that occur on a discrete acyl carrier protein (ACP), SfaO. An amide synthetase, SfaP, catalyzes the amidation of (2S)-2-ethylmalonyl in a SfaO-dependent manner...
April 7, 2023: Angewandte Chemie
https://read.qxmd.com/read/37010769/synthesis-of-stably-charged-arg-trna-arg-for-structural-analysis
#40
JOURNAL ARTICLE
Yuka Yamaki, Howard Gamper, Ya-Ming Hou
Posttranslational protein arginylation catalyzed by arginyl transferases is a mechanism to regulate multiple physiological processes. This protein arginylation reaction uses a charged Arg-tRNAArg as the donor of arginine (Arg). The inherent instability of the ester linkage of the arginyl group to the tRNA, which is sensitive to hydrolysis at the physiological pH, makes it difficult to obtain structural information on how the arginyl transfer reaction is catalyzed. Here, we describe a methodology to synthesize stably charged Arg-tRNAArg that would facilitate structural analysis...
2023: Methods in Molecular Biology
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