Enzyme Mechanisms: Serine Proteases

Slides:



Advertisements
Similar presentations
Fundamentals of Biochemistry
Advertisements

Enzyme Mechanisms C483 Spring 2013.
Mechanisms of Enzyme Action. What You Need to Know Understand the importance of and need for enzymes in biological reactions. Understand how an enzymes.
Principles of Biochemistry
Catalytic Strategies. Basic Catalytic Principles What is meant by the binding energy as it relates to enzyme substrate interactions? –free energy released.
Lecture 17 –Exams in Chemistry office with M’Lis. Please show your ID to her to pick up your exam. –Quiz on Friday –Enzyme mechanisms.
© 2011 Pearson Education, Inc. 1 Organic Chemistry 6 th Edition Paula Yurkanis Bruice Chapter 24 Catalysis.
Hypothetical substrate docking in enzyme’s active site. Substrate is geometrically and electronically compatible with active site. Enzymes are also.
Enzyme Mechanisms.
OMICS Group Contact us at: OMICS Group International through its Open Access Initiative is committed to make genuine and.
Modes of Enzymatic Catalysis 1._________________ modes A.General _______________ Catalysis B.__________________ Catalysis 2.___________________ modes A.______________________.
Lipase B (from Candida antarctica). Introduction Lipases are a group of enzymes that hydrolyze triglycerides at the lipid- water interface. Triglycerides.
Chymotrypsin Chymotrypsin is one of the serine proteases.
Lecture 13: Mechanism of Chymotrypsin
Mechanisms of Enzyme Action
Catalytic Mechanism of Chymotrypsin slide 1 Chymotrypsin –Protease: catalyze hydrolysis of proteins in small intestine –Specificity: Peptide bond on carboxyl.
Average = = C+ Standard deviation = 16 A = 131+B- = A- = C+ = B+ = C = B= C- =
Design of a novel globular protein with atomic-level accuracy.
Two Substrate Reactions
Probing Mechanisms of Peptide Bond Formation & Catalysis Using Models Model of Koga Uses molecular recognition by a crown ether to bind a model of the.
ENZYMES.
Proteolysis.
Chapter 3 PROTEIN FUNCTION. All proteins bind to other molecules Binding is selective.
Chapter 14 Mechanisms of Enzyme Action
The Nature of the Active Site Questions we want to ask: 1.Looking at the reactants and products, what type of reaction has occurred Hydrolysis, Condensation,
Review Enzyme “constants” Reversible inhibition
Chapter 3 DRUG TARGETS: ENZYMES.
Chapter 14 Mechanisms of Enzyme Action
LEHNINGER PRINCIPLES OF BIOCHEMISTRY
Chymotrypsin Lecture Aims: to understand (1) the catalytic strategies used by enzymes and (2) the mechanism of chymotrypsin.
Review session for exam-III Lectures The concept of “induced fit” refers to the fact that: A. Enzyme specificity is induced by enzyme-substrate.
Enzyme Mechanisms and Inhibition
Catalytic Mechanisms.
Enzymes (If you don’t have the energy, we can help!)
Mechanism of lysozyme Lysozyme digests bacterial cell walls by breaking  (1- 4) glycosidic bonds between (N- acetylmuramic acid (NAM) and N-acetylglucosamine.
CHMI E.R. Gauthier, Ph.D. 1 CHMI 2227E Biochemistry I Enzymes: - catalysis.
Six classes of enzymes.
Mechanisms of Enzyme Action. Transition (TS) State Intermediate Transition state = unstable high-energy intermediate Rate of rxn depends on the frequency.
CHMI E.R. Gauthier, Ph.D. 1 CHMI 2227E Biochemistry I Enzymes: - catalysis.
Fundamentals of Biochemistry
Enzyme Activity. ______________________ are broken and made between one or more substances to create new substances. In the process energy is absorbed.
Binding features that promote catalysis
Time to Connect……. Enzyme Activity is amount of enzyme that
Enzyme Rate Enhancement
How Enzymes Work Pratt & Cornely Ch 6.
How Enzymes Work Pratt & Cornely Ch 6.
Enzymes: A Molecular Perspective
Enzymes: the proteins in our body that get the chemical reactions necessary of life done common enzyme found in nearly all living organisms which are exposed.
Zymogen/proenzyme (inactive enzyme precursor)
Serine Proteases Components of the enzymatic pocket:
Trypsin and Chymotrypsin
Serine Proteases A large group of enzymes that cleave amide bond
OMICS Journals are welcoming Submissions
PROTEINS AS DRUG TARGETS:
Enzyme Catalytic Mechanisms
CHYMOTRYPSIN INTRO MISSION: STRATEGY: PROFILE: RELATIVES: SUSPECTS:
Chemistry 501 Handout 6 Enzymes Chapter 6
Enzyme Mechanisms.
Introduction to Enzymes
The Nature of the Active Site
An Introduction to Medicinal Chemistry 3/e PROTEINS AS DRUG TARGETS:
What enzymes are regulated?
An Introduction to Medicinal Chemistry 3/e PROTEINS AS DRUG TARGETS:
Serine proteases Named because they use a serine residue to cut peptide bonds Possess a catalytic triad His 57 Asp 102 Ser 195 Use 2 different types of.
Serine proteases have a reactive serine
Enzymes.
Figure Number: 24-01b Title: Figure 24.1(b)
Enzyme-Substrate Complex
o They are mainly proteins o They are biological catalysts that speed up the rate of the biochemical reaction.
Enzymes.
Presentation transcript:

Enzyme Mechanisms: Serine Proteases C483 Spring 2013

Questions 1. The substrate specificity of serine proteases is primarily due to A) a specificity pocket in the protein. B) the positions of specific side chains of serine, histidine, and aspartate. C) distinct backbone conformations of the individual proteins. D) A and B. E) A, B and C. 2. The role of serine at the active site of serine proteases is to act as a(n) ________ catalyst, while the histidine residue serves as a(n) ________ catalyst. A) strong; weak B) weak; strong C) acid-base; covalent D) covalent; acid-base E) anionic; ionic 3. Experiments on the bacterial serine protease subtilisin show that even when all three residues of the catalytic triad are mutated, the catalytic rate of the enzyme is still 3000 times the uncatalyzed reaction rate. Which mode of catalysis is likely responsible for this remaining catalytic activity? A) Acid-base catalysis. B) Covalent catalysis. C) Induced fit. D) Hydrophobic effects. E) Transition-state stabilization.

Proteases Role in Digestion Zymogens Serine Proteases Homology Chymotrypsin Trypsin Elastase Homology

Selectivity of Serine Proteases

Mechanism of Serine Proteases: Catalytic Triad

Chemical Mechanism Substrate binding affects Histidine base strength Covalent catalysis Oxyanion hole Covalent intermediate

Chemical Mechanism Read from bottom! General acid-base catalysis Oxyanion hole Return to initial state Compare/contrast to Main Protease

Answers A D E