Fig 2

Recombinantly expressed zebrafish s100 proteins are folded and respond to calcium.

(A) Overlaid AlphaFold2 structure predictions for all zebrafish s100 homodimers in this dataset, as well as the human S100A8/S100A9 heterodimer (5W1F RCSB ID). Different chains of each homodimer are shown in black or white. (B) Far UV circular dichroism spectra for each protein in the presence of 2 mM Ca⁺⁺ (orange) and then adding 5mM EDTA (blue). Units are in molar ellipticity (deg × cm²/dmol) over wavelength (nm). (C) Fluorescence excitation and emission spectra for each protein in the presence or absence of calcium (orange and blue, respectively). The fluorescence units are arbitrary; the x-axis is wavelength in nanometers. Excitation spectra were collected while observing fluorescence at the maximum emission wavelength; emission spectra were collected while exciting at the maximum excitation wavelength.