There have been great expectations regarding the production of a drug to block the enzyme LTA4 hydrolase, which plays a key role in the body's inflammatory response.
However, in clinical trials, such molecules have proven to be only moderately effective. Now, researchers at Karolinska Institutet have successfully refined their understanding of why previous substances have been less effective – and in so doing have produced a molecule that gets around the problem. Consequently, there is once again hope of a new anti-inflammatory drug based on the principal of blocking LTA4 hydrolase, which could provide relief in diseases such as COPD, the vascular disease arteriosclerosis and chronic eczema.
The enzyme LTA4 hydrolase has two functions. One is to produce LTB4, which contributes to the inflammatory reaction. The other is to inactivate the tripeptide Pro-Gly-Pro, which is formed during degradation of connective tissue and which also contributes to inflammation. In the first pathway, the enzyme LTA4 hydrolase evokes an inflammatory process, while it contributes to healing in the second.
"It could be considered remarkable that the same enzyme has two activities that are completely opposite. But this is more understandable if you look at it over time: in the first stage, the enzyme creates inflammation at the site of an injury, thus attracting white blood cells, and in the second stage it contributes to healing by inhibiting the inflammation," says Jesper Z. Haeggström, Professor of Molecular Eicosanoid Research in the Department of Medical Biochemistry and Biophysics at Karolinska Institutet.
Previous attempts to produce an anti-inflammatory drug that blocks LTA4 hydrolase have knocked out both of these functions. This is probably why the effects have so far been only moderate. Using x-ray crystallography to study LTA4 hydrolase, Jesper Z. Haeggström and his colleagues have been able to demonstrate that the formation of LTB4, which contributes to the inflammatory process and the inactivation of Pro-Gly-Pro, takes place at different parts of the enzyme's active site – the part of the enzyme used for biochemical communication.
They have used this information to produce a molecule that inhibits LTA4 hydrolase from producing LTB4, while the inactivation of Pro-Gly-Pro is maintained. This means that LTA4 hydrolase acts as an anti-inflammatory in both pathways; awakening new hopes of producing a drug that acts on this enzyme.
In the long-term, the researchers believe that a drug based on their molecule could be used to treat COPD (chronic obstructive pulmonary disease), arteriosclerosis and various types of inflammatory skin disease such as chronic eczema. The study has been financed by the Swedish Research Council, the EU, VINNOVA, Stockholm County Council and Dr. Hans Kröner Graduiertenkolleg.
Publication: 'Binding of Pro-Gly-Pro at the active site of leukotriene A4 hydrolase and development of an epoxide hydrolase selective inhibitor', Alena Stsiapanava, Ulrika Olsson, Min Wan, Thea Kleinschmidt, Dorothea Rutishauser, Roman Zubarev, Bengt Samuelsson, Agnes Rinaldo-Matthis and Jesper Z. Haeggström, PNAS, online early edition 3-7 March 2014.
Karolinska Institutet - a medical university: ki.se/english
Press Office | EurekAlert!
Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory
How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy