Journal: The Journal of Clinical Investigation

Article Title: Enterobacteria secrete an inhibitor of Pseudomonas virulence during clinical bacteriuria

doi: 10.1172/JCI92464

Figure Lengend Snippet: (A) Multiple chemical characterizations identify escherichelin as HPTT-COOH, a compound shown to inhibit pyochelin-mediated iron uptake in Pseudomonas. The positions of 13C salicylate incorporation are indicated in green, while MS/MS neutral losses are indicated as dashed lines. (B) Mass spectra at the retention time for escherichelin from WT UTI89, UTI89ΔybtS, and 13C6-SA–supplemented UTI89ΔybtS culture supernatants revealed that 6 carbons in escherichelin are derived from salicylate. (C) MS/MS product ion spectrum of escherichelin. The 46-Da neutral loss indicates the presence of a carboxylic acid group, and the 87- and 104-Da losses correspond to fragmentation within the thiazoline ring. (D) UV-visible absorption spectra of purified escherichelin incubated with equimolar FeCl3 or CuSO4. (E and F) DFT simulations of escherichelin bound to Fe(III) in a 1:1 (E) and 2:1 (F) complex. The simulations predict stable Fe(III)-escherichelin complexes with hexacoordinate octahedral geometry. (G) UTI89 growth curve in the presence or absence of a ferric ion chelator (0.5 mM EDDHA) and/or ferric ion supplementation (1 μM FeCl3). Growth was monitored by OD at 600 nm (OD600). Data represent the mean of 3, with SD plotted. (H) PW5011 (pvdA-E02::ISlacZ/hah), a P. aeruginosa strain MPAO1 transposon mutant (55, 56) expressing pyochelin as its sole siderophore, was grown in succinate medium for 20 hours in the presence of increasing escherichelin concentrations relative to vehicle control. Bacterial growth was quantified by enumerating CFU/ml and is expressed as a percentage of the vehicle control. Data represent the mean of 3, with the SEM plotted. *P < 0.01 and **P < 0.001, by 1-way ANOVA with Dunnett’s multiple comparisons test.

Article Snippet: The eluate was dried down with a lyophilizer (Labconco), resuspended in 20% methanol, and further purified on a Bio-Rad BioLogic DuoFlow 10 system equipped with a QuadTec UV-Vis detector and a Kromasil Eternity-5-phenylhexyl column (AkzoNobel).

Techniques: Tandem Mass Spectroscopy, Derivative Assay, Purification, Incubation, Mutagenesis, Expressing

Journal: Acta Pharmaceutica Sinica. B

Article Title: Tumor microenvironments self-activated nanoscale metal-organic frameworks for ferroptosis based cancer chemodynamic/photothermal/chemo therapy

doi: 10.1016/j.apsb.2021.01.016

Figure Lengend Snippet: (A) TEM images of FCS MOFs and STEM-EDS elemental maps of FCSP MOFs. (B) Nitrogen adsorption–desorption isotherms of FCS MOFs. (C) UV–Vis spectra of FCSP MOFs, FCSP@DOX MOFs and free DOX. (D) Photothermal stability of FCSP MOFs within five cycles of NIR laser irradiation. (E) Temperature change curses of the FCSP MOFs aqueous dispersion at different power density at the same concentrations of 250 μg/mL. (F) Temperature change curses of the FCSP MOFs aqueous dispersion at different concentrations at the power density of 0.7 W/cm 2 .

Article Snippet: An UV-2600 UV–Vis spectrophotometer from Shimadzu was applied to note the UV–Vis absorption spectra.

Techniques: Adsorption, Irradiation

Journal: Acta Pharmaceutica Sinica. B

Article Title: Tumor microenvironments self-activated nanoscale metal-organic frameworks for ferroptosis based cancer chemodynamic/photothermal/chemo therapy

doi: 10.1016/j.apsb.2021.01.016

Figure Lengend Snippet: (A) TEM images of biodegradable FCSP MOFs immersed in 10 mmol/L GSH aqueous solution for Days 0, 1, 3 and 5. (B) Liquid chromatography-mass spectrometry (LC–MS) results about the reaction between FCSP MOFs and GSH after 0, 3, and 5 days. (C) UV–Vis analysis of the Fenton reaction for RhB decolorization of different groups to demonstrate the ability of ·OH generation and (D) their relative quantification at 553 nm. (E) UV–Vis analysis of the Fenton reaction for RhB decolorization of different groups to demonstrate the ability of heat and Cu 2+ enhanced ·OH generation and (F) their relative quantification at 553 nm. (G) Release kinetics of DOX from FCSP@DOX MOFs in PBS at different pH without or with 10 mmol/L GSH and (H) their relative quantification of DOX release at 72 h. Date are presented as mean ± SD ( n = 3).

Article Snippet: An UV-2600 UV–Vis spectrophotometer from Shimadzu was applied to note the UV–Vis absorption spectra.

Techniques: Liquid Chromatography, Mass Spectrometry, Liquid Chromatography with Mass Spectroscopy

Journal: Nature chemical biology

Article Title: Mitochondrial metabolism promotes adaptation to proteotoxic stress

doi: 10.1038/s41589-019-0291-9

Figure Lengend Snippet: a , Chemical shift perturbation results mapped onto a diagram of the structure of FDX1. Color code: grey, not significantly affected (Δδ NH < 0.01 ppm); blue, significant chemical shift changes (Δδ NH > 0.01 ppm); red, severe line broadening; grey, no assignments. The [2Fe-2S] cluster in FDX1 is indicated by spheres. b , Schematic describing mitochondrial Fe-S cluster biosynthesis. The mitochondrial ISC (iron-sulfur cluster) core complex catalyzes the conversion of cysteine to alanine and generates S 0 for iron sulfur cluster assembly. S 0 is reduced by FDX1. A [2Fe-2S] cluster is subsequently formed on the scaffold protein ISCU. c , In vitro Fe-S cluster assembly was monitored by following the increase of absorbance at 456 nm. Reduced FDX1 was used as a reducing agent in the presence or absence of either 5X (green) or 10X (blue) elesclomol. Data is representative of two independent experiments d , Electron transfer from reduced FDX1 to the cysteine desulfurase complex was measured upon the addition of cysteine in the presence or absence of elesclomol. Data is representative of two independent experiments e , The molecular structure of elesclomol analogs and their corresponding calculated EC50s (from T47D cells grown in Hi-Mito state). The reactive sulfur substitution with an oxygene is indicated with an asterisk. f , The UV/vis spectra of reduced FDX1 before and after incubation with elesclomol-Cu(II) or Cu(II) alone.

Article Snippet: After mixing, the reactions were immediately transferred to 1-cm path-length quartz cuvettes, sealed with rubber septa, taken out of the anaerobic chamber and placed in a Shimadzu UV-1700 UV/vis spectrophotometer equipped with a temperature control system.

Techniques: In Vitro, Incubation