Figure 4. Dynamic studies of statherin on HAP crystals. CPMAS spectra were acquired at room temperature on a home-built 500-MHz spectrometer with spinning speeds of 3, 4, and 5 kHz. Cross-polarization was accomplished with a 2-msec contact time at RF fields of 50 kHz, and data were collected during 100-kHz proton decoupling. T₁ measurements were done at a spinning speed of 6 kHz on a Chemagnetics Infinity 300 with ¹³C spin lock times of 0.05 to 4.55 msec at an RF field of 42 kHz after 1.5 msec of cross-polarization with 70-kHz proton decoupling during acquisition.