Kinetics of Cationic-Ligand-Exchange Reactions in Au₂₅ Nanoclusters

Herein, we report the first investigation into the kinetics of cationic-ligand-exchange processes through the reaction of Au₂₅(SCH₂CH₂Ph)₁₈ with a cationic thiol HS­(CH₂)₁₁N­(CH₃)₃⁺, which resulted in different populations of the two thiolate ligands (SR⁰ and SR⁺), that is, Au₂₅(SR⁰)_{18–<i>x</i>}(SR⁺)_<i>x</i>. The ligand-exchange process was monitored by electrospray ionization mass spectrometry, and the reaction kinetics is discussed in combination with ¹H NMR results; these techniques reveal that the kinetics of the cationic-ligand-exchange process, which is different from a typical neutral-thiol-to-neutral-thiol ligand exchange, is strongly dependent on how the SR⁺ ligands interact with each other during the ligand-exchange process. There are two main factors that determine the unique reaction kinetics, namely, Coulombic repulsions (i) between the attached SR⁺ ligands and free ligands in solution, which hinder further ligand exchange, and (ii) among the surface SR⁺ ligands on the thiolate monolayer, which promote the thermal decomposition of the nanocluster

Correlation of serum IL-37 levels with pro-inflammatory cytokines as well as laboratory values.

<p>Each symbol represents an individual GD patient. (A–C) Serum IL-37 levels were positively correlated with pro-inflammatory cytokine TNF-a, IL-6, IL-17. (D) Negative relationship was observed between serum IL-37 levels and TSH. (E-G) Positively relationship was observed between serum IL-37 levels and FT3, FT4, TRAB. The correlations were evaluated with Spearman's non-parametric test.</p

The demographic and clinical characteristics of the participants.

<p>TSH, thyrotropin; FT4, free thyroxin; FT3, free triiodothyronine; TRAB, thyrotropin receptor antibody; TPOAb, thyroid peroxidase antibody; TgAb, thyroglobulin antibody; Data shown are the case number or median (range). (mg,Propylthiouracil,Methimazole).</p><p>The demographic and clinical characteristics of the participants.</p

Comparison the protein levels of IL-37 and inflammatory cytokines between GD patients and HCs.

<p>(A) Serum IL-37 protein levels in GD patients (n = 40) and healthy controls (HC, n = 30) were determined by ELISA. (B) Serum cytokine TNF-a, IL-6 and IL-17 concentrations in GD patients (n = 40) and HCs (n = 30) were analyzed with ELISA. Each symbol represents an individual GD patient and HC. Horizontal lines indicate median values. Mann-Whitney U-test and associated p values are indicated.</p

Comparison of mRNA levels of IL-37 and cytokines between GD patients and HCs.

<p>(A) Expressions of IL-37 mRNA in PBMC from GD patients (n = 40) and HCs (n = 30) were determined by RT-PCR. (B) mRNA levels of cytokines TNF-a,IL-6 and IL-17 in GD patients (n = 40) and HCs (n = 30) were analyzed with RT-PCR. Results were depicted as box plots, with median (horizontal line within each box) and 10th, 25th, 75th, and 90th percentiles (bottom bar, bottom of box, top of box, and top bar, respectively).</p

IL-37 inhibits the expression of inflammatory cytokines in PBMCs of patients with GD.

<p>PBMCs from GD patients (n = 40) and HCs (n = 30) were stimulated with recombinant IL-37 (100 ng/ml) for 4 h, total RNAs were extracted and analyzed for TNF-α(A), IL-6(B) and IL-17(C) mRNAs by RT-PCR. Results were depicted as box plots, with median (horizontal line within each box) and 10th, 25th, 75th, and 90th percentiles (bottom bar, bottom of box, top of box, and top bar, respectively). The PBMCs of GD patients and HCs from above the same groups were stimulated with recombinant IL-37 (100 ng/ml) for 24 h and then further stimulated with LPS(1 ng/mL) for 6 h, supernatants were collected and examined for TNF-α (D), IL-6 (E) and IL-17 (F) levels by ELISA. Each symbol represents an individual patient or healthy control. Horizontal lines indicate median values. Actual P values are shown in the graph, NS, no significant.</p

Sucrose gradient analysis.

<p>Lysates were layered onto 10–50% sucrose gradients for ultracentrifugation. Ten fractions were taken from top to bottom. (A) SDS-PAGE analysis. The ten fractions were separated by SDS-PAGE, and subsequently stained with Coomassie Blue dye. M, protein marker. EV, purified whole virion EV71 standard from Hualan Inc. (B) Western blotting with anti-VP0 polyclonal antibody. (C) Western blotting with anti-VP1 polyclonal antibody. (D) Western blotting with anti-VP3 polyclonal antibody.</p

Diagrams of the constructs used in this study.

<p>lef2, the left sequence for homologous recombination; hr5-Enh, AcNPV hr5 enhancer; IE1-P, IE1 immediate early promoter; p10-P, p10 promoter; IE1-T, IE1 terminator; 1629, the right sequence for homologous recombination.</p