1. CHMI 2227 - E.R. Gauthier, Ph.D. 1 CHMI 2227E Biochemistry I Enzymes: - catalysis

2. CHMI 2227 - E.R. Gauthier, Ph.D.2 Enzyme catalysis

3. CHMI 2227 - E.R. Gauthier, Ph.D.3 Enzyme catalysis Basic reaction mechanisms  General acid/base catalysis: Three main types of catalysis are found:  Covalent catalysis:  Metal ion catalysis:

4. CHMI 2227 - E.R. Gauthier, Ph.D.4 Enzyme catalysis General acid/base catalysis Chymotrypsin O OH R HOR + H

5. CHMI 2227 - E.R. Gauthier, Ph.D.5 Enzyme catalysis Metal ion catalysis H+H+

6. CHMI 2227 - E.R. Gauthier, Ph.D.6 Enzyme catalysis Covalent catalysis Nucleophile

7. CHMI 2227 - E.R. Gauthier, Ph.D.7 Enzyme catalysis Refresher – nucleophiles and electrophiles

8. CHMI 2227 - E.R. Gauthier, Ph.D.8 Enzyme catalysis - Enzymes often combine two catalytic strategies General Acid/ base catalysis Covalent catalysis

9. CHMI 2227 - E.R. Gauthier, Ph.D.9 Example of enzyme catalysis 1. Chymotrypsin

10. CHMI 2227 - E.R. Gauthier, Ph.D.10 Example of enzyme catalysis 1. Chymotrypsin

11. CHMI 2227 - E.R. Gauthier, Ph.D.11 Example of enzyme catalysis Importance of the catalytic triad

12. CHMI 2227 - E.R. Gauthier, Ph.D.12 Example of enzyme catalysis 1. Chymotrypsin - specificity

13. CHMI 2227 - E.R. Gauthier, Ph.D.13 Example of enzyme catalysis 1. Chymotrypsin - specificity Ser 195

14. CHMI 2227 - E.R. Gauthier, Ph.D.14 Example of enzyme catalysis 1. Chymotrypsin - catalysis Catalytic triad Substrate C-ter part of the protein N-ter part of the protein Peptide bond cleavage Enzyme regeneration Covalent intermediate

15. CHMI 2227 - E.R. Gauthier, Ph.D.15 Example of enzyme catalysis 1. Chymotrypsin - catalysis

16. CHMI 2227 - E.R. Gauthier, Ph.D.16 Example of enzyme catalysis Similarities between different proteases

17. CHMI 2227 - E.R. Gauthier, Ph.D.17 Example of enzyme catalysis Similarities between different proteases

18. CHMI 2227 - E.R. Gauthier, Ph.D.18 Example of enzyme catalysis 2. Enolase

19. CHMI 2227 - E.R. Gauthier, Ph.D.19 Example of enzyme catalysis 2. Enolase

20. CHMI 2227 - E.R. Gauthier, Ph.D.20 Example of enzyme catalysis 2. Enolase

21. CHMI 2227 - E.R. Gauthier, Ph.D.21 Example of enzyme catalysis 3. Lysozyme

22. CHMI 2227 - E.R. Gauthier, Ph.D.22 Example of enzyme catalysis 3. Lysozyme Sugar portion of peptidoglycan

23. CHMI 2227 - E.R. Gauthier, Ph.D.23 Example of enzyme catalysis 3. Lysozyme

24. CHMI 2227 - E.R. Gauthier, Ph.D.24 Example of enzyme catalysis 3. Lysozyme H2OH2O 2