chmi 2227 - e.r. gauthier, ph.d. 1 chmi 2227e biochemistry i enzymes: - catalysis
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CHMI 2227 - E.R. Gauthier, Ph.D. 1
CHMI 2227EBiochemistry I
Enzymes:- catalysis
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Enzyme catalysis
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Enzyme catalysisBasic reaction mechanisms
General acid/base catalysis:
Three main types of catalysis are found:
Covalent catalysis: Metal ion catalysis:
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Enzyme catalysisGeneral acid/base catalysis
Chymotrypsin
O
OHR
HOR
+
H
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Enzyme catalysisMetal ion catalysis
H+
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Enzyme catalysisCovalent catalysis
Nucleophile
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Enzyme catalysisRefresher – nucleophiles and electrophiles
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Enzyme catalysis- Enzymes often combine two catalytic strategies
General Acid/base catalysis
Covalent catalysis
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Example of enzyme catalysis1. Chymotrypsin
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Example of enzyme catalysis1. Chymotrypsin
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Example of enzyme catalysisImportance of the catalytic triad
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Example of enzyme catalysis1. Chymotrypsin - specificity
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Example of enzyme catalysis1. Chymotrypsin - specificity
Ser195 Ser195
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Example of enzyme catalysis1. Chymotrypsin - catalysis
Catalytic triad
Substrate
C-ter part of the protein
N-ter part of the protein
Peptide bond cleavage
Enzyme regeneration
Covalent intermediate
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Example of enzyme catalysis1. Chymotrypsin - catalysis
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Example of enzyme catalysisSimilarities between different proteases
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Example of enzyme catalysisSimilarities between different proteases
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Example of enzyme catalysis2. Enolase
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Example of enzyme catalysis2. Enolase
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Example of enzyme catalysis2. Enolase
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Example of enzyme catalysis3. Lysozyme
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Example of enzyme catalysis3. Lysozyme
Sugar portion of peptidoglycan
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Example of enzyme catalysis3. Lysozyme
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Example of enzyme catalysis3. Lysozyme
H2O
2