Related Experiment Video
Updated: Sep 18, 2025
09:42
Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes
Published on: January 16, 2016
9.1K
Enzymatic Reactions Dictated by the 2D Membrane Environment
Ru-Hsuan Bai1, Chun-Chen Lin1, Chun-Wei Lin1
1Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 300044.
The Journal of Physical Chemistry Letters
|June 24, 2025
Summary
The cell membrane enhances enzyme activity but also limits it through diffusion. Adjusting enzyme-membrane interactions allows enzymes to "hop," overcoming limitations for sustained high reaction rates.
Area of Science:
- Biochemistry
- Cell Biology
- Physical Chemistry
Background:
- Cell membranes act as physical barriers and platforms for biochemical reactions.
- Membrane environments impose unique physical constraints on surface reactions.
- The advantages and limitations of membrane-mediated reactions are not fully understood.
Purpose of the Study:
- To investigate the impact of the membrane environment on enzymatic reactions.
- To analyze enzyme-substrate interactions at the single-molecule level.
- To explore how enzyme-membrane affinity influences reaction kinetics.
Main Methods:
- Reconstitution of a proteolytic cleavage reaction at the membrane interface.
- Real-time kinetic analysis at the single-molecule level.
- Systematic alteration of enzyme-membrane affinity.
Main Results:
- Membrane environment enhances enzymatic turnover rate.
- Diffusion limitations arise, reducing turnover rate over time.
- Intermediate enzyme-membrane affinity allows "hopping," overcoming diffusion limits and sustaining high turnover rates.
Conclusions:
- The cell membrane plays a dual role, enhancing reactivity while imposing physical limitations.
- Dynamic tuning of membrane affinity optimizes enzymatic processes.
- Provides a framework for understanding membrane-associated interactions in biological systems.
Related Concept Videos
01:24Protein Diffusion in the Membrane
4.6K
Proteins show rotational as well as lateral diffusion across the membrane. The lateral diffusion of proteins was confirmed through the cell fusion experiment where mouse and human cells were fused, resulting in hybrid cells. When the human and mouse cells fused, the specific membrane proteins on human and mouse cells were marked with the red and green-fluorescent markers, respectively. Initially, the red and green fluorescence was located on the respective hemisphere of the cell. As time...
4.6K
01:15Mechanisms of Membrane-bending
2.9K
The living membranes are flexible due to their fluid mosaic nature; however, their bending into different shapes is an active process regulated by specific lipids and proteins. The membrane bending can be transient as seen in vesicles or stable for a long time as in microvilli. Cells regulate the size, location, and duration of the membrane curvature.
Membrane bending can happen due to intrinsic changes in lipid composition or extrinsic association with different proteins. The proteins involved...
Membrane bending can happen due to intrinsic changes in lipid composition or extrinsic association with different proteins. The proteins involved...
2.9K
01:35Asymmetric Lipid Bilayer
7.9K
Biological membranes show uneven distribution of different types of lipids in the inner and outer layers, resulting in transverse asymmetric membranes. The treatment of the erythrocyte membrane with the enzyme phospholipase confirmed the asymmetric nature of the lipid bilayer. The enzyme hydrolyzes lipids into fatty acids and hydrophilic groups. The phospholipase acts only on the outer layer of the membrane, while the inner layer remains intact. The phospholipase treatment resulted in 80%...
7.9K
00:59Mechanisms of Membrane Domain Formation
3.2K
Different physical properties of lipids and proteins allow them to localize and form distinct islands or domains in the membrane. Some membrane domains are formed due to protein-protein interactions, whereas others are formed due to the presence of specific lipids such as sphingolipids and sterols—for example, large proteins, such as bacteriorhodopsin, aggregate and create distinct domains.
Another mechanism for membrane domain formation involves membrane proteins interacting with...
Another mechanism for membrane domain formation involves membrane proteins interacting with...
3.2K
02:34Enzymes
82.9K
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...
82.9K
01:13Introduction to Mechanisms of Enzyme Catalysis
8.9K
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...
8.9K