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              Printable Handouts
Navigable Slide Index
- Introduction
 - Outline
 - The general modifier mechanism
 - The general modifier mechanism: the reaction
 - The principle of microscopic reversibility
 - But this is impossible
 - Make it easier with node compression
 - Generalized microscopic reversibility
 - Cleland’s definition of sticky substrate
 - The original equation by Botts & Morales
 - Analysis of the Botts-Morales equation
 - Simplification
 - Further simplification
 - Rate equation when equilibrium conditions prevail
 - All reactions are in steady-state (SS)
 - The vertical steps are in quasi-equilibrium (QE)
 - All steps are in quasi-equilibrium (QE)
 - Generalized microscopic reversibility
 - An assessment for the validity of quasi-equilibrium
 - From the recommendations 1981
 - Systematics of enzyme-modifier interactions
 - Two ancestors and a prolific hybrid
 - The first branch: 1 < α < ∞
 - The second branch: 0 < α < 1
 - The third branch: α = 1
 - The basic modifier mechanisms
 - Nomenclature of the basic modifier mechanisms
 - Systematics = taxonomy + nomenclature
 - Nature’s strategies in three specialized levels
 - Allosteric interactions
 - The liberator: guardian angel in enzyme-regulation
 - Disclosure of the basic modifier mechanism
 - Parameter dependence on modifier concentration
 - The critical specific velocity
 - The specific velocity equation
 - The specific velocity plot (primary)
 - The specific velocity plot (secondary)
 - Human lipoxygenases (EC 1.13.11.-)
 - Arachidonate 15-lipoxygenase (EC 1.13.11.33)
 - The dual mechanisms as traffic lights
 - Drug hunting and high throughput screening
 - Theoretical and practical support
 
Topics Covered
- Regulation of enzyme activity by inhibitors and activators called modifiers
 - General modifier mechanism proposed by Botts and Morales
 - Fundamental laws of enzyme kinetics
 - A systematic approach to a taxonomic ranking of enzyme-modifier interactions
 - The pivotal role of allosteric interactions in the supervision of enzyme activity
 
Links
Series:
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External Links
Talk Citation
Baici, A. (2023, March 30). Nature’s strategies in the regulation of enzyme activity by modifiers [Video file]. In The Biomedical & Life Sciences Collection, Henry Stewart Talks. Retrieved November 4, 2025, from https://doi.org/10.69645/GEKL5436.Export Citation (RIS)
Publication History
- Published on March 30, 2023
 
Financial Disclosures
- There are no commercial/financial matters to disclose.
 
A selection of talks on Methods
Transcript
Please wait while the transcript is being prepared...
      
      
        
                  0:00
                
                
                  
                    Welcome everybody to this
talk on the regulation of
                  
                    enzyme activity by
inhibitors and activators.
                  
                    My name is Antonio Baici,
                  
                    retired from the
University of Zurich.
                  
                    I have been active in the
field of enzyme kinetics,
                  
                    investigating the
theoretical aspects
                  
                    of enzyme inhibition
                  
                    with obligations to
                  
                    pathological degradation
of connective tissues.
                  
                
              
                  0:25
                
                
                  
                    In this talk, I will
bring to your attention
                  
                    the kinetic groundwork of
enzyme modifier interruptions.
                  
                    I will start with
                  
                    the general modifier mechanism
                  
                    and some principles
of enzyme kinetics.
                  
                    The present nomenclature of
                  
                    enzyme inhibitors and
activators is answered
                  
                    dissatisfactorally, this is partly
due to the non observance of
                  
                    the recommendations issued by
                  
                    the International Union of
                  
                    biochemistry and
Molecular Biology and
                  
                    partly to merging
                  
                    unrelated mechanisms
under collected names.
                  
                    I will describe a
systematics treatment
                  
                    of modifier mechanisms,
                  
                    which is entirely based on
                  
                    the recommendations and on
                  
                    the general modifier mechanism.
                  
                    Don't worry for names, concepts,
                  
                    and the definitions
possibly new to you.
                  
                    You can re-examine them on links
                  
                    I will show in the last slide.
                  
                    The intended purpose
of this talk
                  
                    is to illustrate a
logical approach to
                  
                    the investigation of enzyme
                  
                    modified interactions with
                  
                    emphasis on allosteric
regulation.
                  
                
              
                  1:33
                
                
                  
                    Jean Botts and her husband
Manuel Francisco Morales,
                  
                    wrote a fundamental paper on
                  
                    enzyme modifier
interactions. The term
                  
                    modify in the title
                  
                    declares the intention of
treating every kind of
                  
                    enzyme inhibition and
activation under the same roof.
                  
                    An important statement
at the beginning of
                  
                    the mathematical
derivation seems to have
                  
                    been underestimated by
the scientific community.
                  
                    For the discussion
of this effect,
                  
                    one may visualize and
                  
                    enzymatic patch upon
the enzyme molecule,
                  
                    consisting of an enzymatic site
                  
                    which bind substrate molecules,
                  
                    and then adjacent side which
binds modifier molecules.
                  
                    The highlighted adjacent
side is evidently
                  
                    a less spectacular definition
of allostatic site,
                  
                    published 10 years later in
                  
                    the famous paper by
mono and co-workers.
                  
                    Moreover, Botts and Morales
                  
                    published a complete
mathematical treatment,
                  
                    not found on all papers.
                  
                
              
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