CHAPTER 7 - CATALYSIS
B: MECHANISMS OF ENZYME CATALYSIS
BIOCHEMISTRY - DR. JAKUBOWSKI
004/12/16
Learning Goals/Objectives for Chapter 7B: After class and
this reading, students will be able to
- identify the types of catalysis used in enzyme-catalyzed
reactions given a detailed mechanism;
- interpret kinetic experiments experiments varying substrate,
inhibitors, pH, ion strength, and amino acid side chains
(through chemical modification or site-specific mutagenesis) to
better understand the catalytic mechanisms utilized in
enzyme-catalyzed reactions;
- identify potential rate limiting steps in enzyme catalyzed
reaction mechanisms and simplify kinetic equations based on
them;
- generally describe the diversity, the critical active site
residues and the biological activities of proteases;
- describe the structure/function of the proteasome.
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B8. Links and References
The
Enzyme Function Initiative is
developing such tools to predict in vitro enzymatic and in vivo
physiological functions of unknown enzymes.
Uniprot,
a web base resources that hold protein sequence and functional
information, has over 44 million protein sequences (derived from nucleotide
sequences) and most have no well defined protein function.
Metabolic
Docker: uses molecular docking as a basis for predicting the
function of enzymes. It supports docking both ground state and high energy
intermediate forms of metabolites and commercially available compounds to
protein structures
Other Types of Enzymes
The three enzymes studied above are all
hydrolases - enzymes that catalyze the hydrolysis of bonds (either amide or
acetal). This is only one class of six different reaction types that
have been categorized by the
Enzyme Commission of
the International Union of Biochemistry and Molecular Biology. The six
types (all external links) include:
EC1:
Oxidioreductases - oxdiation/reduction reactions (we will discuss these
in Chapter 8B)
EC2:
Transferases - acyl, glycosyl, 1C, N, O, aldehydes, ketones, etc
EC3:
Hydrolases
EC4: Lyases
- cleavage of C-C, C-O, C-N, C-S, etc. bonds
EC5:
Isomerases - racemases, epimerases, cis-trans isomerases
EC6: Ligases
- form C-C, C-O, C-N, etc bonds
Other Links
Enzyme
Nomenclature Database: Interactive site to search information on
enzymes using EC system of nomenclature.
BRENDA:
(Brauschweig Enzyme Database) Comprehensive Enzyme Information System
KEGG
PATHWAY: collection of manually drawn pathway maps
representing our knowledge on the molecular interaction and reaction
networks using KEGG, Kyoto
Encyclopedia of Genes and Genomes
FMM
(From Metabolite to Metabolite) - reconstructs metabolic pathways from one
metabolite to another
References
- Fuguo Jiang and Jennifer A. Doudna. CRISPR–Cas9 Structures and
Mechanisms. Annu. Rev. Biophys. 2017. 46:505–29
- Giulia Palermo et al. Striking Plasticity of CRISPR-Cas9 and Key
Role of Non-target DNA, as Revealed by Molecular Simulations. ACS
Cent. Sci. 2016, 2, 756−763
- Ryan Cross, CRISPR’s breakthrough problem. Chem. Eng. News. pg
28. February 13, 2017
- John van der Oost, New Tool for Genome Surgery. Science, 339,
pg 768 (2013)
- Wolan, D. et al. Small-Molecule Activators of a Proenzyme. Science
326, 853 (2009)
- Wang, Y. et al. Crystal structure of a rhomboid family intramembrane
protease. Nature. 444, 179 (2006)
- Freeman, M. Proteolysis within the membrane: rhomboids revealed.
Nature Reviews: Molecular Cell Biology. 5, p 188 (2004)
- Borman, S. Much ado about enzyme mechanisms. C&EN. pg 35 (Feb 23,
2004)
- Garcia-Cioloca, M. Goa, J., Karplus, M. and Truhlar, D. How Enzymes
Work: Analysis by modern rate theory and computer simulation Science.
303, pg 186 (2004)
- Benkovic, St. & Hammes-Schiffer, S. A Perspective on Enzyme
Catalysis. Science. 301, pg 1196 (2003)
- Takasugi, N. et al. The role of presenilin cofactors in the
γ-secretase complex. Nature. 422, pg 438 (2003)
- Weihofen et al. Identification of Signal Peptide Peptidase, a
Presenilin-Type Aspartic Protease. Science, 296, pp. 2156, 2215,
- Vocadlo. D. et al. Catalysis by hen egg-white lysozyme proceeds via
a covalent intermediate. Nature. 412. pg 835 (2001)
- Walsh, C. Enabling the Chemistry of Life. Great review article on
enzymes mechanisms. Nature. 409, pg 226 (2001)
- Koeller and Wong. Enzymes for Chemical Synthesis. Nature 409. pg
232 (2001)
- Simeonov et al. Blue-Fluorescent Antibodies. Science. 290, pg 286,
307 (2000)
- Huntington et al. Structure of a serpin-protease complex shows
inhibition by deformation. Nature. 407, pg 923 (2000)
- New Way to Study Closely related proteins (remodeling proteins to
make them more susceptible to inhibition) Science 289. pg 2029 (2000)
- Vocadlo et al. Catalysis by hen egg-white lysozyme proceeds via a
covalent intermediate. Nature. 412. pg 835 (2001)
- Istan and Deisenhofer. Structural Mechanism for Statin Inhibition of
HMG-CoA Reductase. Science. 292, pg 1160 (2001)
- Heine et al. Observations of Covalent Intermediates in an Enzyme
Mechanism at Atomic Resolution. Science 294. pg 369 (2001)
- Carpenter et al. Structure of dehydorquinate synthase reveals an
active site capable of multi-step catalysis. Nature. 394, pg 299 (1998)
- Kohen et al. Tunnel Vision (on why
activity of therophilic enzymes (>60oC) is low or absent at mesophilic
temperatures (< 40oC) - from reduction of flexibility of thermophilic
enzymes at mesophilic temperatures - quantum tunneling explanation).
Nature. 399, pg 417, 496 (1999)
- Finnin et al. Structure of a histone deacetylase homologue bound to
the TSA and SAHA inhibitors (and mechanism). Nature. pg 189, September
1999.
- Ondrechen. THEMATICS: A simple
computational predictor of enzyme function from structure. Proc. Natl.
Acad. Sci. USA, 98, pg 12473 (2001 )
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Methods of Enzyme Catalysis
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Mechanisms
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