Trypsin cleaves polypeptide chains at the carboxyl side of a lysine or arginine residue. Chymotrypsin cleaves polypeptide chains on the carboxyl side of an aromatic amino acid residue or nonpolar, bulky side chain. Which is more specific?

Phosphorylation is a very common post-translational modication (PTM) to regulate protein function. Which amino acids are most commonly regulated by phosphorylation? Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer. a Leucine, arginine, serine. b Tyrosine, arginine, glutamine. C Serine, threonine, tyrosine. d Glutamine, arginine, tyrosine. e Serine, tyrosine, glutamine.

What general structural feature is shared by proteins that specifically form homodimers (but not homotrimers, homoteramers etc)? Only one answer is correct.     the surface consists of hydrophilic alpha-helix.   the surface is highly modified by post-translational modification.   the surface is permanently bound by chaperones.   the surface is unstructured.   the surface, or part of it, is self-complementary.

Given the following diagram of how protein AWESOME1 binds to it's target DNA, describe the potential effects of each of the 5 mutations shown below. The wild-type sequence of a helix #1 is also shown in the blue box, and all the mutations are in helix #1 (see numbers for identifying particular residues). a helix #1 R(1)-V-I-L-Y-F-W-I-M-Y-F-S-H-Y-W-R(16) #1 Predict the consequence of the following mutations: 1) Arg(1) to Glu 2) Arg(1) to Ala 3) Phe(6) to lle 4) Trp(7) to Phe 5) Met(9) to Pro in