Structure Analysis by X-ray Scattering

For an example of structure analysis by X-ray scattering, see D. I. Svergun, S. Richard, M. H. Koch, Z. Sayers, S. Kuprin, and G. Zaccai, Protein hydration in solution experimental observation by X-ray and neutron scattering, Proc. Natl Acad. 3d. USA 95,2267-2272, 1998. 

The intended role of the glycylalanine repeats in this design is the formation of p-sheet crystalline stems,7.8 while residues X and Y are chosen to form reverse tums.9,10 In each case, the selection of local sequence elements was based on information about the conformational properties of known polypeptides poly(glycylalanine) has been reported to form p-sheet crystals, , and Sibanda and Thornton have identified five X,Y pairs that appear to favor p-hairpin formation in globular proteins.9,10 As of this writing, we have expressed six different sequence variants of 1, and several chain-length variants as well. Detailed structural analysis by x-ray scattering and spectroscopic methods is underway and will be repotted elsewhere. 

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