Do you want to create a universal cure for the flu? Ask me how!
The flu doesn't have long to live
Alexandra Borisova, "Newspaper.Ru»
Scientists have managed to decipher the structure of a protein whose mutations are responsible for the variability of the influenza virus. The search for chemicals that effectively bind to its active sites will lead to the creation of a truly universal vaccine capable of defeating a rapidly mutating virus.
Is there any hope that one of the scourges of humanity, especially the pestering people in the autumn-winter period, will be finally defeated? Scientists say that yes. Two independent groups (from the University of Iowa and the University of Florida) published in Science data on the exact decoding of the structure of one of the flu proteins. This information will help predict all types of possible mutations of the virus and produce highly effective medicines for any of them.
Every season, doctors face the same task – to determine in the shortest possible time the type of seasonal influenza virus that will spread this year. The variability of the influenza virus does not allow creating a universal vaccine against it, so they are produced anew every year. However, due to the variability of the virus, the high rate and variety of its mutations, vaccines developed in previous years are useless against a new type of disease. That is why the development of vaccines against the highly virulent (characterized by a large scale of spread) H1N1 swine flu virus was carried out so quickly last year.
Moreover, antiviral drugs that have proven themselves well lose their effectiveness. Amantadine used since 1969 (simadine and symmetrel drugs) and rimantadine (flumadine) are no longer on the lists recommended by the US Center for Infectious Diseases Control.
For half a century, the virus has changed a lot: drugs defeated it by blocking the work on the surface of the membrane of the viral envelope of one of the proteins (it is called M2), which does not exist in modern viruses in the "traditional" form.
This protein is responsible for changing the hydrogen index (pH), that is, the chemical hardness of the medium – acidic or alkaline – inside the cell. Only with his participation, the genetic material of the virus is able to penetrate into the cell and begin to multiply there. In the "new" viruses, the spatial structure of M2 has changed markedly, and in such cases, even a slight variation in the distance between the atoms and their relative position in space does not allow the drug to bind to the protein and makes it unusable.
Both scientific groups studied the protein structure using modifications of one of the most effective modern methods of studying the structure of biomolecules – nuclear magnetic resonance spectroscopy (NMR). For the development of this method, Swiss Kurt Wuterich received half of the Nobel Prize in Chemistry in 2002. However, Wuterich was engaged in the study of biomolecules in solution, and the structure of M2 was determined using NMR in the solid phase.
The NMR method is based on the analysis of the spectrum arising from the interaction of atomic nuclei in complex molecules with electromagnetic radiation. The nature of this interaction depends on the environment of the atom, therefore, the spectrum can be used to understand the structure of the entire molecule, "collecting" it from the particles of the environment of each individual atom.
NMR is used in various modifications. In addition to the phase in which the substance under study is located, the frequency of the radiation used, the strength of the magnetic field changes, the environment of certain types of atoms is analyzed. In the experiments described by Science, the "diamonds" of the NMR technique were used – a spectrometer with a magnet weighing 40 tons, which allows to achieve a radiation frequency of 900 MHz.
The study of the structure of the M2 protein showed how it mutated and which types of mutations are dangerous, that is, develop the pathogenicity of the virus, and which lead to its "falling asleep", preventing it from infecting healthy host cells. Thus, a circle of dangerous M2 mutations was identified, which must be combated. The presence of such a limited set allows us to begin work on the search for biologically active substances that can potentially bind to the active sites of this protein and, thus, block its work in the cells of the human body.
"The resistance of viruses and bacteria to drugs is a fundamental problem of modern medicine. Its origins are in the incorrect, insufficient or, conversely, excessive use of drugs," said chemistry professor Timothy Cross, director of the NMR program at the University of Florida and co–author of one of the articles.
"In this work, we were able to identify the basic foundations of how mutations affect the work of the virus, change its properties. Without this knowledge, it is impossible to consciously approach the search for medicines to combat them. We have published the exact structure of the "target", which should be targeted by targeted therapeutic drugs of the future. Now we can start shooting," summed up one of the authors of the work, biophysicist David Busat.
Portal "Eternal youth" http://vechnayamolodost.ru22.10.2010