Is RNA-binding enzyme RNase A more likely to have a pI of 9.2 or 5.0?Briefly explain your reasoning.

Suppose you have a solution of a protein, which contains a specific Tyr residue that has an actual (measured) pKa of 8.8. The protein binds a ligand by several noncovalent interactions, one of which is a hydrogen bond in which the Tyr phenolic hydroxyl group must serve as a hydrogen bond donor. Calculate the percentage of the protein molecules in which that tyrosyl residue's phenolic hydroxyl group could serve as a hydrogen bond donor at pH 8.5

Answer a and b

A researcher isolates a new protein and finds that it contains 0.755% serine by weight upon amino acid analysis. The molecular mass of serine is 105 g.mol-¹. What is the minimum molecular mass for the protein assuming only one Ser residue per protein molecule? mmin = The researcher estimates the molecular mass of the protein using gel electrophoresis. From this estimated molecular mass, the researcher concludes the protein contains 3 Ser residues. What is the estimated molecular mass of the protein as shown by gel electrophoresis? g.mol-¹ mest = g.mol-1

This SDS-PAGE loading buffer has SDS (a denaturing detergent), β-mercaptoethanol (a reducing agent), Coomassie Blue (a dye), and glycerol. You will need to dilute your protein samples such that the final concentration of the loading buffer is 1x, meaning that you will add 5 parts of the protein sample for every 1 part of 6x buffer. Calculate how much of the 6x loading buffer you will need to add to each sample. Then, add the appropriate amount of 6x SDS-PAGE loading buffer to the samples. Store the samples in the -20°C freezer. What is the final concentration of glycerol in each of the samples?