Question

The active site of lysozyme contains two amino acid residues essential for catalysis: Glu-35 and Asp-52. The pKa values of the carboxyl side chains of these residues are 6.5 and 4.2, respectively. What is the pH optimum of lysozyme based on the plot of pH versus rate, below? What is the ionization state (protonated or deprotonated) of each residue at this pH optimum? Which of these residues, either Glu-35 or Asp-52 act as a base in the catalytic mechanism, consistent with these data. EXPLANATION PLZ

Answer 1

Lysozyme is a characteristic antibacterial specialist found in tears also, egg whites. The substrate of lysozyme is peptidoglycan, a starch found in numerous bacterias. Lysozyme separates the glycosidic C-O covalent bond between the two kinds of sugar buildup in the atom, N-acetylmuramic acid (Mur2Ac) and N-acetylglucosamine (GlcNAc) , frequently alluded to as NAM and NAG, individually. The activity of lysozyme is ideal at pH 5.2 and diminishes above and underneath this pH. At this pH Glu35 protonated on account of higher pKa and Asp52 deprotonated. In the enzyme catalysis general acid catalysis by Asp52 protonates the GlcNAc oxygen and encourages its going. General base catalysis by Glu35 encourages the atack of water on the glycosyl carbocation.