Transfusion medicine

The study find that the treatment of thrombosis, the leading cause of death among cancer patients. Because  In a study to be publish in Blood, the scientists describe the Ixolaris structure; therefore an important anticoagulant protein find in tick saliva, and its interaction with Factor Xa, a key enzyme in the process of blood clotting.

Description of the molecular

Ana Paula Valente, Viviane de Paula; Robson Monteiro and Fabio C. L. Almeida, of the Federal University of Rio de Janeiro, in collaboration with Nikolaos Sgourakis; of the University of California, Santa Cruz, and Ivo Francischetti, of the National Institute of Health; in the United States; conducted the study.

The anticoagulant effects of Ixolaris are already know; but this is the first description of the molecular mechanism of its action on the functioning of Factor Xa; therefore an enzyme that plays a crucial role in the blood clotting. Using nuclear magnetic resonance; the researchers were able to construct a 3-D model of the structure formed by the association of these two proteins.

The molecular mechanism

The unprecedent result brings important insights into understanding the molecular mechanisms behind hemostasis; a complex process that regulates blood clotting and whose malfunction can lead to thrombosis. The expectation is that, from such a study, it will be possible to develop drugs capable of interrupting the formation of clots without interfering in the process of hemostasis as a whole.

Nuclear magnetic resonance (NMR) is a property that magnetic nuclei have in a magnetic field and applied electromagnetic (EM) pulse; which cause the nuclei to absorb energy from the EM pulse and radiate this energy back out. Therefore The energy radiated back out is at a specific resonance frequency which depends on the strength of the magnetic field and other factors. This allows the observation of specific quantum mechanical magnetic properties of an atomic nucleus.

Specific resonance frequency

Many scientific techniques exploit NMR phenomena to study molecular physics; crystals and non-crystalline materials through NMR spectroscopy. NMR is also routinely use in advance medical imaging techniques, such as in magnetic resonance imaging (MRI).A key feature of NMR is that the resonance frequency of a particular substance is directly proportional to the strength of the apply magnetic field.

It is this feature that is exploited in imaging techniques; if a sample is place in a non-uniform magnetic field then the resonance frequencies of the sample’s nuclei depend on where in the field they are located. Since the resolution of the imaging techniques depends on how big the gradient of the field is, many efforts are made to develop more powerful magnets, often using superconductors. The effectiveness of NMR can also be improved using hyper polarization, and/or using two-dimensional, three-dimensional and higher dimension multi-frequency techniques.