Using structure to elucidate function mechanism
Download
1 / 9

Using Structure to Elucidate Function/Mechanism - PowerPoint PPT Presentation


  • 136 Views
  • Uploaded on

Using Structure to Elucidate Function/Mechanism. An experimental strategy for. determining the arrangement of atoms/molecules in space to obtain structural information. Some situations in which this strategy might be applied. understand a mechanism in detail

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Using Structure to Elucidate Function/Mechanism' - chaeli


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

An experimental strategy for

  • determining the arrangement of atoms/molecules in space to obtain structural information


Some situations in which this strategy might be applied

  • understand a mechanism in detail

  • structure-based (rational) drug design

  • elucidate a novel structure

  • understand a conformational switch (e.g. prions)


Some methods that provide structural information:

  • X ray bombardment of crystals

  • circular dichroism (CD)

  • nuclear magnetic resonance (NMR)- size < 25 kD

  • sequence comparison/analysis (e.g. COILS or threading)- surface residues are most conserved

  • electron microscopy (EM)

  • atomic force microscopy

  • photo/chemical cross-linking

  • protease digestion

  • calorimetry

  • sedimentation


Circular Dichroism

The differential absorption of radiation polarized in two directions as a function of frequency is called dichroism.Circular dichroism (CD) spectroscopy is a form of light absorption spectroscopy that measures the difference in absorbance of right- and left-circularly polarized light (rather than the commonly used absorbance of isotropic light) by a substance.

http://broccoli.mfn.ki.se/pps_course_96/ss_960723_21.html

Kurt D. Berndt


Circular Dichroism

Circular dichroism is very sensitive to the secondary structure of polypeptides and proteins.

http://broccoli.mfn.ki.se/pps_course_96/ss_960723_21.html

Kurt D. Berndt


What are the experimental prerequisites for structural studies?

  • material for study should be of homogeneous composition. How?

  • often useful to reduce the complexity of the problem by focusing on a subregion of a larger molecule. How?

  • minimize flexibility of the molecule in solution so that only a small number of conformations are possible. How?


What are possible pitfalls of crystallographic studies? studies?

  • biologically irrelevant structure? Less common than you might think.

  • faulty interpretation. Interfaces that form during packing of molecules into a crystal may not be biologically relevant. Solution?


ad