A Designed beta-Hairpin Containing a Natural Hydrophobic Cluster This research was supported by the National Science Foundation (CHE-9820952). J.F.E. was supported by a fellowship from the Ministerio de Educacion y Cultura (Spain) and the Fulbright Commission. The mass spectrometer was purchased in part with a National Science Foundation grant (CHE-9520868), and the NMR spectrometers were purchased in part with a National Institute Of Health grant (1 S10 RR04981). The CD spectrometer and analytical ultracentrifuge are part of the UW Biophysics Instrumentation Facility (NSF BIR-9512577).