exponential plateau model  (GraphPad Software Inc)

Journal: The Journal of Biological Chemistry

Article Title: The polar amino acid in the TatA transmembrane helix is not strictly necessary for protein function

doi: 10.1016/j.jbc.2023.102998

Figure Lengend Snippet: Quantitative analyses of the Tat activity in the TatA Q8 variants.A, plot of the transport kinetics of the TatA Q8 variants in pulse-chase experiments. Identities of wtTatA and TatA Q8 variants are shown in the right. Mature/total denotes the ratio of the mature band to the sum of the precursor and mature bands revealed by autoradiography of the samples from the pulse-chase experiment transporting SufI; chase time is denoted on the abscissa. Lines show best fits of an exponential model to the points arising from at least two biological replicates for each mutant. B, plot of the initial velocities (V0) in the TatA Q8 variants transporting SufI. Exact values of the V0 are shown above the bars. TatA Q8 variants are grouped based on classification of the amino acids.

Article Snippet: Mature-to-total (sum of precursor and mature) data from the pulse-chase experiment were plotted against each time point, which were then fitted with the exponential plateau model deriving from the first-order reaction model, y = ( y max − y 0 ) × e − k t , using GraphPad Prism. y max was defined as the maximum of the mature-to-total value, and y 0 represents the initial mature-to-total value at the end of the pulse. t represents time in minutes.

Techniques: Activity Assay, Pulse Chase, Autoradiography, Mutagenesis