Sulfur Single-Wavelength Anomalous Diffraction
Authors:
- Students:
- Nynika Badam
- Jonathan Barker
- Sahaja Danthurthy
- Hariharan Kannan
- Ayush Khot
- Sannidhi Mohan
- Pravallika Padyala
- Xitali Sanchez
- Diya Sharma
- Rohan Vanjani
- Zachary White
- Teachers:
- Jonathan Ogrodnik
- Vanessa Troiani
- Mentors:
- Erica Duguid (Hauptman Woodward Medical Research Institute, Advanced Photon Source, IMCA-CAT)
Advanced Photon Source Sector 17: IMCA-CAT
The purpose of this experiment was to learn the mechanics of x-ray crystallography in conjunction with modern technology in order to discern the atomic and molecular structure of bovine insulin. Bovine insulin is a two-chain polypeptide hormone found in the pancreatic cells of cows, and it was chosen as the subject protein due to easy accessibility and an easily comprehensible structure. Initially, the bovine insulin was crystallized with the hanging drop method within a well of reservoir solution made up of Na3PO4, H2O, and EDTA, yielding cuboidal crystals of medium-large size. At the Advanced Photon Source at Argonne National Laboratories, the S-SAD process was used, a method in which a particle accelerator shoots electrons at extremely high velocities to find the structure of the molecule. The crystallized samples were placed on nylon loops and shock-cooled before being placed into the beamline. These crystals were hit by high-powered x-ray photons generated from the advanced photon source. While on the beamline the sample will be turned 180 degrees. This will create an electron configuration chart from the diffractions of the photons based upon the position of the electrons in the samples. The data will then be analyzed then used to map the structure of the protein bovine insulin.