Related Experiment Video
Updated: Jan 25, 2026
05:37
Single-Molecule Fluorescence Visualization of DNA Polymerase Dynamics at G-Quadruplexes
Published on: April 4, 2025
1.2K
Light-controlled thrombin catalysis and clot formation using a photoswitchable G-quadruplex DNA aptamer
Aysha Ali1, Gemma A Bullen, Benjamin Cross
1School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK. j.tucker@bham.ac.uk.
Chemical Communications (Cambridge, England)
|April 27, 2019
Summary
Researchers demonstrate reversible photocontrol of blood coagulation using a modified thrombin binding aptamer (TBA). Light triggers structural changes, inhibiting thrombin and controlling clotting.
Area of Science:
- Biochemistry
- Molecular Biology
- Biotechnology
Background:
- Blood coagulation is a complex process involving enzymes like thrombin.
- Controlling coagulation is crucial for treating bleeding disorders and thrombosis.
- Existing methods for coagulation control can be invasive or lack precise temporal regulation.
Purpose of the Study:
- To develop a light-controllable system for regulating blood coagulation.
- To demonstrate reversible photocontrol of thrombin activity using a modified aptamer.
Main Methods:
- Modification of thrombin binding aptamer (TBA) with two anthracene groups to render it photochromic.
- Induction of anthracene photodimerization using light to alter TBA structure.
- Assessment of the effect of light-induced structural changes on thrombin binding and subsequent coagulation activity.
Main Results:
- Light-triggered photodimerization of anthracene groups caused structural distortion of the TBA.
- The distorted TBA exhibited inhibited binding to thrombin.
- This inhibition of thrombin binding reversibly controlled the blood clotting process.
Conclusions:
- Reversible photocontrol of blood coagulation is achievable through light-modulated aptamer structure.
- Photochromic aptamers offer a novel, non-invasive strategy for regulating enzyme activity.
- This approach has potential applications in hemostasis and thrombosis management.
Related Concept Videos
02:50Catalysis
30.2K
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
30.2K
01:16Precipitate Formation and Particle Size Control
6.3K
In precipitation gravimetry, the precipitating agent should react specifically or selectively with the analyte. While a specific reagent reacts with the analyte alone, a selective reagent can react with a limited number of chemical species.
The obtained precipitate should be either a pure substance of known composition or easily converted to one by a simple process, such as ignition or drying. In addition, the precipitate should be insoluble and easily filterable. In general, filterability...
The obtained precipitate should be either a pure substance of known composition or easily converted to one by a simple process, such as ignition or drying. In addition, the precipitate should be insoluble and easily filterable. In general, filterability...
6.3K
01:13Introduction to Mechanisms of Enzyme Catalysis
10.5K
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...
10.5K
01:16Clot Retraction and Fibrinolysis
8.6K
After a fibrin clot is formed, the next step is clot retraction, a vital process facilitated by platelet contractile proteins, such as actin and myosin. These proteins pull the fibrin strands closer together and condense the clot. This action reduces the size of the clot, creating a smaller, denser structure that effectively seals off the damaged vessel. Clot retraction consolidates the clot and helps with wound healing by bringing the edges of the damaged blood vessel closer together.
8.6K
02:16Light Acquisition
9.4K
In order to produce glucose, plants need to capture sufficient light energy. Many modern plants have evolved leaves specialized for light acquisition. Leaves can be only millimeters in width or tens of meters wide, depending on the environment. Due to competition for sunlight, evolution has driven the evolution of increasingly larger leaves and taller plants, to avoid shading by their neighbors with contaminant elaboration of root architecture and mechanisms to transport water and nutrients.
9.4K
00:55DNA Helicases
23.9K
DNA unwinding helicase enzymes are a type of motor protein. Motor proteins can translocate along filaments or polymers using energy generated from ATP hydrolysis. Helicases are involved in all the important cellular processes where DNA unwinding is required, such as DNA replication, repair, recombination, and transcription. They are present in all living organisms, but vary in their structure, function, and mechanism of action. For example, in prokaryotes, DnaB helicase binds and translocates...
23.9K