Related Experiment Video
Updated: Jun 6, 2026
09:42
Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes
Published on: January 16, 2016
The role of electrostatic interactions in protease surface diffusion and the consequence for interfacial biocatalysis
Bob E Feller1, James T Kellis, Luis G Cascão-Pereira
1Department of Chemical Engineering, Stanford University, Stanford, California 94305-5025, United States.
Langmuir : the ACS Journal of Surfaces and Colloids
|November 18, 2010
Summary
Electrostatic interactions significantly influence enzyme surface diffusion and biocatalysis. Optimizing enzyme charge and ionic strength can enhance reaction rates by balancing adsorption and diffusion for industrial applications.
Area of Science:
- Biochemistry
- Surface Science
- Enzyme Kinetics
Background:
- Interfacial biocatalysis is crucial for many industrial processes.
- Understanding enzyme surface diffusion and adsorption is key to optimizing biocatalytic efficiency.
- Electrostatic interactions play a significant role in enzyme-substrate binding and activity at interfaces.
Purpose of the Study:
- To investigate the influence of electrostatic interactions on enzyme surface diffusion.
- To determine the contribution of surface diffusion to interfacial biocatalysis.
- To explore strategies for enhancing enzyme activity through surface modification and process design.
Main Methods:
- Utilized fluorescence recovery after photobleaching, surface plasmon resonance, and surface plasmon fluorescence spectroscopy.
- Employed an enzyme charge ladder of bovine serum albumin (BSA) variants with net charges from -2 to +4.
- Manipulated electrostatic interactions by varying solution ionic strength at a fixed pH on an immobilized BSA multilayer substrate.
Main Results:
- Increased ionic strength, weakening electrostatic interactions, significantly enhanced enzyme surface diffusion.
- Maximum reaction rates occurred at intermediate surface concentrations, influenced by enzyme charge.
- Specific enzyme activity increased with decreased adsorption and positively charged enzymes, with diminishing returns for highly charged variants.
Conclusions:
- Enzyme surface diffusion and adsorption are critical factors in interfacial biocatalysis.
- Electrostatic interactions can be controlled via ionic strength and enzyme charge to optimize surface concentration and diffusion.
- A balance between adsorption and surface diffusion determines the maximum reaction rate, offering insights for enzyme engineering and process design in industrial applications.
Related Concept Videos
01:13Introduction to Mechanisms of Enzyme Catalysis
For many years, scientists thought that enzyme-substrate binding took place in a simple "lock-and-key" fashion. This model stated that the enzyme and substrate fit together perfectly in one instantaneous step. However, current research supports a more refined view scientists call induced fit. The induced-fit model expands upon the lock-and-key model by describing a more dynamic interaction between enzyme and substrate. As the enzyme and substrate come together, their interaction causes a mild...
02:04Protein-protein Interfaces
Many proteins form complexes to carry out their functions, making protein-protein interactions (PPIs) essential for an organism's survival. Most PPIs are stabilized by numerous weak noncovalent chemical forces. The physical shape of the interfaces determines the way two proteins interact. Many globular proteins have closely-matching shapes on their surfaces, which form a large number of weak bonds. Additionally, many PPIs occur between two helices or between a surface cleft and a polypeptide...
01:13Induced-fit Model
Most chemical reactions in cells require enzymes—biological catalysts that speed up the reaction without being consumed or permanently changed. They reduce the activation energy needed to convert the reactants into products. Enzymes are proteins, that usually work by binding to a substrate—a reactant molecule that they act upon.
Enzymes exhibit substrate specificity, meaning that they can only bind to certain substrates. This is mainly determined by the shape and chemical characteristics of...
Enzymes exhibit substrate specificity, meaning that they can only bind to certain substrates. This is mainly determined by the shape and chemical characteristics of...
02:34Enzymes
Inside living organisms, enzymes act as catalysts for many biochemical reactions involved in cellular metabolism. The role of enzymes is to reduce the activation energies of biochemical reactions by forming complexes with its substrates. The lowering of activation energies favor an increase in the rates of biochemical reactions.
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
01:06Interfacial Electrochemical Methods: Overview
Interfacial electrochemical methods focus on the phenomena occurring at the boundary between an electrode and a solution, as opposed to bulk methods that concentrate on the solution's overall properties. These interfacial methods are classified as either static or dynamic based on the presence of a nonzero current in the electrochemical cell and the consistency of analyte concentrations. Static methods, such as potentiometry, measure the cell's potential without any significant current passing...
01:07Catalytically Perfect Enzymes
The theory of catalytically perfect enzymes was first proposed by W.J. Albery and J. R. Knowles in 1976. These enzymes catalyze biochemical reactions at high-speed. Their catalytic efficiency values range from 108-109 M-1s-1. These enzymes are also called 'diffusion-controlled' as the only rate-limiting step in the catalysis is that of the substrate diffusion into the active site. Examples include triose phosphate isomerase, fumarase, and superoxide dismutase.