Sketch the Hill plot for a system with negative cooperativity. Be sure to a) label your axes, and to indicate in your plot: b) the Hill constant, c) limiting slopes, d) Kd values and what binding site the Kd values correspond to.

A one-to-one protein (P)-ligand (L) complexation (P + L PL) has a dissociation equilibrium constant (Kd) value of 100 nM at 25°C, and the Kd remains the same at 37°C. 1) What is AS of binding at 25°C? Assume ACp of the binding is 0 over the temperature range. AS = 1.34E2 kJ/(mol*K) (note the unit!!) (sig. fig =3) 2) What is the concentration of the PL complex formed at equilibrium when you mix 0.20 uM (microM) of Protein and 1.0 uM of Ligand together at 37°C? PL at equilibrium = 8.1E-1 uM (note the unit!!) (sig. fig =2)

1)Ubiquitin is a small protein with a monoisotopic mass of 8560 Da. a) Electrospray ionization of this small protein typically results in major charge states of +8, +9, +10, +11, +12, and +13.  Using this information, complete the table below, assuming the charges on each come from protonation.  Report mass and m/z values to the ones place.  b) Using the data you entered in the table, sketch an expected ESI-MS spectrum for ubiquitin. Label each peak with its charge state.  What do you notice about the spacing of peaks along the x-axis. c)The figure shows an experimentally obtained electrospray mass spectrum for ubiquitin. Compare this spectrum to the spectrum you predicted. Are there any differences? If so, what might cause these differences?

In an electrostatic interaction, the strength of the bond is: Oa) proportional to the charges on the two interacting atoms. b) proportional to the dielectric constant of the medium. c) proportional to the charges of the two atoms and to the dielectric constant of the medium. d) proportional to the Charges of the two atoms and inversely proportional to the distance between the two atoms e) inversely proportional to the distance between the two atoms.