Related Experiment Videos
Crystallographic structure of human gamma-thrombin
T J Rydel1, M Yin, K P Padmanabhan
1Department of Chemistry, Michigan State University, East Lansing 48824-1322.
The Journal of Biological Chemistry
|September 2, 1994
Summary
Crystallization efforts unexpectedly yielded gamma-thrombin due to autolysis, revealing structural insights into thrombin
Area of Science:
- Biochemistry
- Structural Biology
- Enzymology
Background:
- Thrombin is a key enzyme in hemostasis.
- Understanding thrombin structure is crucial for drug development.
- Autolysis can alter thrombin's structure and function.
Purpose of the Study:
- To determine the crystal structure of alpha-thrombin complexed with a synthetic peptide inhibitor.
- To investigate the structural consequences of thrombin autolysis.
Main Methods:
- X-ray crystallography
- Gel electrophoresis
- NH2-terminal sequence analysis
- Structural comparison
- Molecular docking
Main Results:
- Crystals of gamma-thrombin, not the intended alpha-thrombin complex, were obtained due to autolysis.
- NH2-terminal sequencing confirmed gamma-thrombin and minor beta-thrombin products.
- The gamma-thrombin structure showed high similarity to alpha-thrombin but with poor electron density at cleavage sites.
- Autolysis disrupted the Lys70-Glu80 loop, impairing exosite functions.
Conclusions:
- Autolysis significantly alters thrombin structure, particularly exosite regions.
- The folded structure of alpha-thrombin is largely preserved despite autolysis.
- Modeling suggests substrate interaction during beta-cleavage involves exosite docking at the active site.