This information can be used to determine the distance between nuclei. Furthermore, the absorption signals of different nuclei may be perturbed by adjacent nuclei. Depending on the environment of atoms within the protein, the nuclei of individual atoms will absorb different frequencies of radio signals. Data collection relies on placing the sample inside a powerful magnet, sending radio frequency signals through the sample, and measuring the absorption of those signals. In contrast to MRI, structural biology studies do not directly generate an image, but rely on complex computer calculations to generate three-dimensional molecular models.Ĭurrently most samples are examined in a solution in water, but methods are being developed to also work with solid samples. This change of scale requires much higher sensitivity of detection and stability for long term measurement. These properties are fundamentally the same as those used in the more familiar magnetic resonance imaging (MRI), but the molecular applications use a somewhat different approach, appropriate to the change of scale from millimeters (of interest to radiologists) to nanometers (bonded atoms are typically a fraction of a nanometer apart), a factor of a million. These properties depend on the local molecular environment, and their measurement provides a map of how the atoms are linked chemically, how close they are in space, and how rapidly they move with respect to each other. NMR involves the quantum-mechanical properties of the central core (" nucleus") of the atom. The sample is prepared, measurements are made, interpretive approaches are applied, and a structure is calculated and validated. Structure determination by NMR spectroscopy usually consists of several phases, each using a separate set of highly specialized techniques. Ernst and Kurt Wüthrich at the ETH, and by Ad Bax, Marius Clore, Angela Gronenborn at the NIH, and Gerhard Wagner at Harvard University, among others. Nuclear magnetic resonance spectroscopy of proteins (usually abbreviated protein NMR) is a field of structural biology in which NMR spectroscopy is used to obtain information about the structure and dynamics of proteins, and also nucleic acids, and their complexes.
0 kommentar(er)
