Metabolism: Researchers first to shed light on structure of huge enzyme complex
2021-02-10
(Press-News.org) A new method has enabled the natural structure of particularly large and complex enzymes to be revealed. Scientists at Martin Luther University Halle-Wittenberg (MLU) and TU Berlin have published their findings in the journal Cell Reports. They investigated a multi-enzyme complex that plays an essential role in metabolism and have discovered that it functions differently than previously thought. This will help scientists better understand certain diseases.
Enzymes are a cell's biocatalysts. They accelerate chemical reactions in the body or ensure that these reactions even take place at all. As a result, they play an extremely important role in metabolism. Individual enzymes frequently form a complex with many subunits, as in the case of the pyruvate dehydrogenase complex. It occurs in all human, animal and plant cells, as well as in fungi and even in some bacteria. "It is vital for energy production in cells," explains Dr Panagiotis Kastritis, an assistant professor at MLU and group leader at the Centre for Innovation Competence HALOmem.
"Up until now, the enzyme complex has always been broken down into its individual parts before being examined. Studying the entire, functional complex is very complicated," says Kastritis. To solve this problem, his team combined various biochemical and biophysical methods of investigation. In addition to using mass spectrometry and chemical analyses, a special form of electron microscopy - cryo-electron microscopy - has been essential for studying such a complex structure, says the structural biologist. It enables complex, organic structures to be observed at a high resolution and in their natural state. "However, it is very important to subsequently bring together all this data in computer models," says Kastritis. For the current study, the team of researchers is using cell extracts of a fungus that can survive at high temperatures, which makes analysis easier.
The scientists have thus gained an insight into how the various subunits of the enzyme complex interact with each other and have also discovered that it functions differently than previously assumed. "It was previously thought that all of the subunits were directly involved in the reaction," says Kastritis. "But now we know that some of them seem to form a kind of chamber that protects the reaction." Because the complexes are very similar across organisms, the results are also helping researchers understand the human pyruvate dehydrogenase complex.
The new method could help scientists better understand many different diseases. Some viruses, for example, reduce the number of enzyme associations in the cells. This effect has also been observed in Alzheimer's disease. In some cases, however, the enzymes do not function properly and the vital reactions occur either too slowly or too quickly. "If we are able to better understand the natural structure, we will be able to recognise tiny changes and understand why the reaction is no longer occurring as it should," says Kastritis. This knowledge could theoretically also form the basis for new treatment options.
INFORMATION:
The study was funded by the Federal Ministry of Education and Research (BMBF), the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), the Wellcome Trust and with funds from the European Regional Development Fund (ERDF).
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
2021-02-10
In a study conducted at the University of Helsinki, Finland, 136 adults adhered to one of three study diets for 12 weeks. One of them corresponded to the average Finnish diet, containing roughly 70% animal-derived protein of total protein, while most of the plant-based protein originated from cereal products. In the second study diet, half of the protein was derived from plant products and the other half from animal products, while the third one contained 30% animal protein and 70% plant-based protein of total protein.
Sources of animal protein, both red and white meat as well as dairy products, were partially replaced with plant-based proteins by adding a diverse range of legumes, nuts, ...
2021-02-10
Your breath holds the key to monitoring fat burning, and now a research group from Tohoku University has created a compact and low-cost device that can measure how our body metabolizes fat.
The device uses an ultraviolet lamp to gauge exhaled acetone gas, which is produced in the blood through the metabolic reaction of fat.
"Precise measurements of acetone gas concentration allows us to determine the body's ability to metabolize fat and develop exercise methods for efficient fat burning," says Professor Yuji Matsuura from Tohoku University's Graduate School of Biomedical ...
2021-02-10
Many natural and human-made networks, such as computer, biological or social networks have a connectivity structure that critically shapes their behavior. The academic field of network science is concerned with analyzing such real-world complex networks and understanding how their structure influences their function or behavior. Examples are the vascular network of our bodies, the network of neurons in our brain, or the network of how an epidemic is spreading through a society.
The need for reliable null models
The analysis of such networks often focuses on finding interesting properties and features. For example, does the structure of a particular contact network help diseases spread ...
2021-02-10
The research team led by Masakazu Ohara, graduate student of the Department of Computer Science and Engineering at Toyohashi University of Technology (student in the Leading Program doctoral program); Associate Professor Kowa Koida of the Electronics-Inspired Interdisciplinary Research Institute; and Associate Professor Juno Kim of the University of New South Wales (Australia) discovered that when people judge the thickness of an object, objects with glass-like transparent optical properties are perceived to be flatter than they actually are. It was previously known that objects made of metallic or glossy materials are perceived to be thicker than what they are, but now the current research has identified that transparent ...
2021-02-10
A description of gravity compatible with the principles of quantum mechanics has long been a widely pursued goal in physics. Existing theories of this 'quantum gravity' often involve mathematical corrections to Heisenberg's Uncertainty Principle (HUP), which quantifies the inherent limits in the accuracy of any quantum measurement. These corrections arise when gravitational interactions are considered, leading to a 'Generalized Uncertainty Principle' (GUP). Two specific GUP models are often used: the first modifies the HUP with a linear correction, while the second introduces a quadratic one. Through new research published in EPJ C, Serena Giardino and Vincenzo ...
2021-02-10
A unique 'heart-shape', with wisps of gas filaments showing an intricate honeycomb-like arrangement, has been discovered at the centre of the iconic supernova remnant, the Crab Nebula. Astronomers have mapped the void in unprecedented detail, creating a realistic three-dimensional reconstruction. The new work is published in Monthly Notices of the Royal Astronomical Society.
The Crab, formally known as Messier 1, exploded as a dramatic supernova in 1054 CE, and was observed over the subsequent months and years by ancient astronomers across the ...
2021-02-10
Dimerization (Note: combination of two identical or different molecules) of the human neuropeptides oxytocin and vasopressin can produce new types of bioactive molecules. In a recent study, an international research team led by MedUni Vienna and the University of Vienna demonstrated that dimerized and therefore significantly larger versions of oxytocin and vasopressin are still able to activate their receptors. Such new constructs provide several opportunities to optimize the efficacy of these neuropeptides for therapeutic application. The researchers were inspired for this approach from naturally occurring dimers. The results have been published in the journal "Chemical Science".
Oxytocin/vasopressin receptors are typical examples of so-called G protein-coupled receptors - the most ...
2021-02-10
In order for a drug to be effective at the right places in the body, it helps if scientists can predict as accurately as possible how the molecules of that drug will interact with human cells. In a joint research project, scientists from Collaborative Research Centre 1423 at Leipzig University and the Chinese Academy of Sciences in Shanghai have succeeded in elucidating such a structure, namely that of the neuropeptide Y receptor Y2 with one of its ligands. This is the first time that a molecular blueprint for this receptor is available, which will enable the development of tailor-made new drugs, for example to treat epilepsy or cardiovascular diseases. The researchers' findings have now been published in Nature Communications.
The Y2 receptor plays ...
2021-02-10
"Insulin is a prime example for a successful peptide drug that has been essential for the health of millions of diabetic patients in the past 100 years," says Markus Muttenthaler, who leads research groups at the Institute of Biological Chemistry of the Faculty of Chemistry at University in Vienna as well as at the Institute for Molecular Bioscience, at the University of Queensland in Brisbane.
Worldwide, peptide therapeutics account for 5% of the global pharmaceutical market, with global sales exceeding US$ 50 billion. More than 150 peptides are in clinical development and another 400-600 peptides undergoing preclinical ...
2021-02-10
Children with epilepsy sleep poorly compared to healthy children, and are more likely to experience disruptions such as night terrors, sleep walking or sleep disordered breathing, according to a new study.
A team at the University of Birmingham's Centre for Human Brain Health analysed 19 published studies on sleep and epilepsy in children and adolescents to try to better understand and articulate the links between them.
Their findings, published in Sleep Medicine Reviews, highlight the significantly poorer sleep experienced by children and adolescents with epilepsy, and present a strong argument for screening children for sleep problems as an integral part of diagnosis and management of the condition.
Lead author Alice Winsor explains: "We know that sleep and epilepsy ...
LAST 30 PRESS RELEASES:
[Press-News.org] Metabolism: Researchers first to shed light on structure of huge enzyme complex
