Tentoxin has at least two binding sites on CF1 and ϵ-depleted CF1 ATPases isolated from spinach chloroplast

AbstractA new procedure for synthesis of 14C-labeled tentoxin [14C-MePhe[(Z)Δ]3-tentoxin], with a high specific activity, is described. Binding experiments with CF1 or CF1-ϵ isolated from spinach chloroplast have been carried out using equilibrium dialysis technique. The results show the presence of two classes of binding sites. The association constants of the two major binding sites were derived from non-linear fitting of the binding curves. At 4°C, the first binding site has a value of Ka1 = 8.2 × 105 M−1 in CF1 and 8.7 × 105 M−1 in CF1-ϵ, while the second binding site has lower affinity with Ka2 = 1.5 × 104 M−1 in CF1 and 2.3 × 103 M−1 in CF1-ϵ

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements