. The mechanism for lysozyme cleavage of its polysaccharide substrate requires Glu35 in itsnonionized form, whereas the nearby Asp52 must be ionized (see the figure below). The pKvalues for the side-chain carboxyl groups on the two amino acids in solution are virtuallyidentical.a) How can one carboxyl group be charged and the other uncharged in the active site oflysozyme?b) The pH optimum for lysozyme is about 5. Why do you suppose that the activity decreasesabove and below this optimum?Glu3sNAGAsp520-HGlu35 -CAsp52tri-NAGNAG

The lysozyme is an enzyme found in the secretions like tears and sweat. It cleaves the glycosidic…

Answered: The mechanism for lysozyme cleavage of…

Biochemistry

6th Edition

ISBN:9781305577206

Author:Reginald H. Garrett, Charles M. Grisham

Publisher:Reginald H. Garrett, Charles M. Grisham

Chapter26: Synthesis And Degradation Of Nucleotides

Section: Chapter Questions

Problem 15P

See similar textbooks

Similar questions

The enzymatic activity of lysozyme is optimal at pH 5.2 and decreases above and below this pH value. Lysozyme contains two amino acid residues in the active site essential for catalysis: Glu35 and Asp52. The pK value for the carboxyl side chains of these two residues are 5.9 and 4.5 respectively. What is the ionization state of each residue at the pH optimum of lysozyme? How can the ionization states of these 2 amino acid residues explain the pH-activity profile of lysozyme?
The active site of lysozyme contains two amino acid residues essential for catalysis: Glu35 and Asp52. The pKa values of the carboxyl side chains of these residues are 5.9 and 4.5, respectively. What is the ionization state(protonated or deprotonated) of each residue at pH 5.2, the pH optimum of lysozyme? How can the ionization states of these residues explain the pH-activity profile of lysozyme shown below?
Briefly describe the induced-fit conformational change when hexokinase binds its substrate.
Within the body, CoQ 10 can be found in an oxidized or reduced form (also known as ubiquinone and ubiquinol). Describe how these structures differ and the biochemical role of coenzyme Q10.
#1 Specify the role each of the following amino acids play within the crystal structure and/or active site for Be as specific as possible, with pictures (and mechanistic arrows) as necessary. His11 Arg140 Glu89 Trp68 #2 Provide a step-wise mechanism for the reaction Bisphosphoglycerate mutase catalyzes, using the amino acids responsible for aiding in catalysis. You do not need to add surrounding amino acids that aid in substrate specificity. (drawn out)
Lysozyme is an enzyme that hydrolyzes bacterial cell wall polysaccharides. When this reaction is carried out in the presence of H218O, it is observed that there is retention of configuration at the C1 carbon of the D site sugar as shown below: Would this result suggest that the enzyme mechanism involves the direct nucleophilic attack of water at C1 or that the enzyme mechanism involves attack by a nucleophilic amino acid side chain of the enzyme that generates a transient covalent intermediate?
a) Based on the mechanism shown in Figure 2A, what type of enzyme is transpeptidase? : Lyase Isomerase Ligase Hydrolase Oxidoreductase Transferase b) Transpeptidases have two substrates. From Figure 2A, what type of mechanism do they most likely adopt in processing the two substrates? sequential or ping-pong c) β-lactams inactivate transpeptidases by forming a covalent bond with the serine residue in the active site. Based on this description and Figure 2B caption, what type of inhibitor are β-lactams? _________________________________________ d) Based on the mechanism for lactamase shown in Figure 3, what type of enzyme is lactamase? Lyase Isomerase Ligase Hydrolase Oxidoreductase Transferase e) Based on your answer in d, what other reactant, in addition to the antibiotic substrate, needs to be in the active site of lactamase for the hydrolysis reaction to proceed? ____________________
Consider applying biocatalytic reduction with carrots to the following two ketones: tert-butyl methyl ketone, and 3-hexanone. Which would you expect to give higher enantioselectivity in biocatalytic reduction? Explain your answer.
Consider the pathway for catabolizing galactose. What are the potential control points for this pathway?
Describe the nitrogenase complex. How is the enzymeorganized? What are its unique components?
Coenzyme-dependent enzymes can catalyze the general transformations shown below.What would be the best coenzymes to use for the two steps in the scheme, and why? Then, proposean enzyme-catalyzed method for step A to proceed without a coenzyme. Show this enzymecatalyzed mechanism for step A that does not require the coenzyme. You can abbreviate acidicamino acid residues “Enz–B–H” and basic residues “ B–Enz”.
The Energy Cost of dTTP Synthesis (Integrates with Chapter 20.) Starting from HCO3, glutamine, aspartate, and ribosc-5-P, how many ATP equivalents are consumed in the synthesis of dTTP in a eukaryotic cell, assuming dihydroorotate oxidation is coupled to oxidative phosphorylation? How does this result compare with the ATP costs of purine nucleotide biosynthesis calculated in problem 2?

SEE MORE QUESTIONS

Recommended textbooks for you

Biochemistry

ISBN:

9781305577206

Author:

Reginald H. Garrett, Charles M. Grisham

Publisher:

Cengage Learning

Biochemistry

ISBN:

9781305577206

Author:

Reginald H. Garrett, Charles M. Grisham

Publisher:

Cengage Learning

SEE MORE TEXTBOOKS