Pseudocontact shift (PCS) contains rich structural information of proteins in structural and chemical biology. F-PCS is determined in live mammalian cells dual labelling of the target protein with a paramagnetic tag and a F-tag, which is achieved by varied reactivity of solvent exposed cysteines in selection of different types of tags. About 0.
View Article and Find Full Text PDFMicroorganisms produce extracellular enzymes to meet elemental requirements and cope with stoichiometric imbalances of resources. To gain insights into the cycling of C, N, and P, the activities of the C∶N∶P acquisition enzymes have been extensively investigated. To detect the effects of long-term fertilization practices on soil nutrient balance and characteristics of soil enzymatic stoichiometry in black soil, four different fertilization treatments were selected: no fertilization (CK), nitrogen fertilizer (N), phosphorus fertilizer (P), and combination of nitrogen and phosphorus fertilizers (NP).
View Article and Find Full Text PDFSite-specific modification of proteins with synthetic fluorescent tag effectively improves the resolution of imaging, and such a labeling method with negligible three-dimensional structural perturbations and minimal impact on the biological functions of proteins is of high interest to dissect the high-resolution activities of biomolecules in complex systems. To this end, several non-emissive iridium(III) complexes [Ir(C-N) (H O) ] OTF (C-N denotes various cyclometalated ligands) were designed and synthesized. These complexes were tested for attaching a protein by coordinating to H/X (HisMet, HisHis, and HisCys) that are separated by i and i+4 in α-helix.
View Article and Find Full Text PDFA Gram-positive strain APA H-16(1) was isolated from a saline-alkali soil sample collected from Heilongjiang Province, China. Cells were rod shaped, non-motile, endospore forming, and aerobic. Growth occurred at 10-45 °C (optimum, 35 °C), pH 7.
View Article and Find Full Text PDFAn alkaliphilic actinobacterial strain, designated Hz 6-5, was isolated from saline-alkaline soil from Songnen Plain in north-eastern China. The isolate formed light yellow-colored colonies and its cells were Gram-staining positive, non-motile, and non-spore-forming short rods. The strain was aerobic with optimal growth at 33 °C, pH 9.
View Article and Find Full Text PDFUnstable and low-abundance protein complexes represent a large family of transient protein complexes that are difficult to characterize, even by means of high-resolution NMR spectroscopy. A method to assign the NMR signals of these unstable complexes through a combination of selective isotope labeling of amino acids in a protein and site-specific labeling the protein with a paramagnetic tag is presented herein. By using this method, the resonances of unstable thioester intermediate complex (lifetime <5 h and highest concentration ≈20 μm) generated by Staphylococcus aureus sortase A and its peptide substrate under a real-time reaction have been assigned.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
June 2016
Scanning Electron Microscope-Energy Dispersive X-ray spectroscopy (SEM-EDX) was applied to analyze the chemical and structural properties of biochars produced under different temperatures. Results showed that average carbon content (SEM C aver.) and maximum carbon content (SEM C max.
View Article and Find Full Text PDFA novel coumarin-based fluorescent probe CF was synthesized for the detection of hydrazine both in aqueous solution and vapor state with high sensitivity and selectivity. Upon addition of hydrazine, the solution of probe CF in MeCN-H2O (3/7, v/v, buffered CH3COOH/CH3COONa) at pH 5.0 exhibited a remarkable change in emission color from pale green to light blue, which could be recognized with naked eyes.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
September 2015
We have developed a novel fluorescent chemosensor (DAM) based on dansyl and morpholine units for the detection of mercury ion with excellent selectivity and sensitivity. In the presence of Hg(2+) in a mixture solution of HEPES buffer (pH 7.5, 20 mM) and MeCN (2/8, v/v) at room temperature, the fluorescence of DAM was almost completely quenched from green to colorless with fast response time.
View Article and Find Full Text PDFWe developed a new dansyl phthalimide-based fluorescent chemosensor for hydrazine detection. Upon a Gabriel type-based hydrazinolysis of dansyl phthalimide (DPI) in the presence of hydrazine in a mixture of HEPES buffer (pH 7.0, 20 mM) and DMSO (1/9, v/v) at room temperature, the chemosensor produces fluorescent dansyl-NH with the maximum emission wavelength changed from 475 nm to 512 nm along with a color change from yellow to colorless, allowing colorimetric detection of hydrazine by the naked eye.
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