Question

The lysozyme mechanism is provided below. What mechanisms of lowering deltaG^‡ are exploited in the lysozyme-catalyzed reaction? Explain each one and how it is functioning in this reaction.

Enzyme Example 4: Lysozyme Breaks down bacterial cell walls Е.С. 3.2.1.17 Cleaves glycosidic linkages between MurNAc and GlcNAC Contains two conserved residues: Glu35 and Asp52 Strain plays important role in mechanism See chapter 11, section 4 (pg. 339-344) muramc acid (MurdAc) CGICNAC E35 D52 Asp52 ES5 35 635 D52 D52 052

Answer 1

Answer:- mechanisms of lowering deltaG‡ are exploited in the lysozyme-catalyzed reaction are as follow:-
1. the enzyme binding to a hexasaccharide unit, distorting the D residue toward half-chair
2. Glu 35 transfers proton to O1 atom bridging the D and E rings, facilitating the cleavage of C1-O1 bond D ring converted to resonance-stabilized oxonium ion stabilized by presence of nearby negatively charged Asp 52; E ring product released
3. Asp 52 nucleophilically attacks electron-poor C1 of the D ring to form covalent intermediates.
4. Water replaces the E-ring product in the active site
5. Hydrolysis of the covalent bond with the assistance of Glu 35.