Synthesis and Evaluation of Chloramphenicol Homodimers: Molecular Target, Antimicrobial Activity, and Toxicity against Human Cells
Fig 3
AcPhe-puromycin synthesis in the presence or absence of compound 5.
(A) First-order time plots; complex C reacted at 25°C in buffer A, with (black) 400 μM puromycin or with a mixture containing 400 μM puromycin and compound 5 at concentrations of 4 μM (magenta), 8 μM (green), 15 μM (blue), and 30 μM (red). (B) Variation of the apparent equilibration rate constant, keq, as a function of compound 5 concentration (I). The reaction was carried out in buffer A, in the presence of puromycin at concentrations of 200 μM (red), 400 μM (black), or 2 mM (blue). The keq values were determined by non linear regression fitting of the kinetic data to Eq 2 [11]: (C) Kinetic model for the inhibition of the puromycin reaction by CAM dimers. Symbols: C, poly(U)-programmed ribosomes from E. coli, bearing AcPhe-tRNAPhe at the P-site of the catalytic center and tRNAPhe at the E-site; I, CAM dimer; S, puromycin; C’, ribosomal complex not recycling; P, AcPhe-puromycin. See also S1 Fig.