A COMPARISON OF X-RAY AND NMR STRUCTURES FOR HUMAN ENDOTHELIN-1

Direct comparisons between the recently solved X-ray and NMR structure s of human endothelin-1 with respect to secondary structure, RMS devia tions, surface accessibilities, and side-chain conformers indicate imp ortant differences in conformation, especially in the C-terminus, but also in the central loop region, that are important for defining the s pecificity of binding. These differences are larger than seen for othe r X-ray and NMR structures that have been compared. Comparisons betwee n the X-ray structure and the NMR NOE constraints highlight the region s of flexibility and environment-induced diversity in the endothelin s tructures.