Fig. 5: Experimental validation of HTML-OSMES candidates.
a Time-resolved 1H NMR spectra of SHMT1 activity in the presence of 5 mM HTML at 0, 35, 65 and 105 min. Cα protons singlet of glycine is assigned in the structure. b Nonlinear fitting to the Michaelis Menten equation of the dependency on HTML concentrations of the initial reaction velocity of SHMT1 (1 μM). Data are presented as mean values ± SEM; n = 4 independent experiments for each point. c Kinetic parameters (kcat, Km, kcat/Km) of HTMLA reaction of tested enzymes with mean and standard deviation values obtained by nonlinear fitting. The blue-white gradient indicates better (blue) or worse (white) values in each column, where better means higher for kcat and kcat/Km or lower for Km. d Scheme of the broken bond (magenta cross) in the aldol cleavage reactions of HTML, L-allo-threonine, L-threonine. In red are the portions common to the three substrates. e Bar plot in log scale of the catalytic efficiency of different enzymes (Tha1, SHMT1, SHMT2) with different substrates (HTML, L-allo-threonine, L-threonine). The data points correspond to the kcat/Km values and the error bars represent the standard deviations of the fitting parameters. f Lineweaver-Burk double-reciprocal primary plot of the inhibition by HTML of kynurenine aminotransferase activity of KYAT1. The kynurenine concentration ranged from 0.75 to 3 mM. The concentrations of HTML were 0, 2, 4, and 8 mM. Source data are provided as a Source Data file.
