Soft-Pulsed Aluminum-27 Quadrupolar Central Transition NMR Studies of Ovotransferrin

We have employed soft (Gaussian) pulses to examine²⁷Al NMR signals arising from Al³⁺bound to ovotransferrin. In addition to enhancing the general detectability of²⁷Al signals from a practical standpoint, this technique makes it possible to invert the central component of the protein-bound²⁷Al signals, providing a route for, to our knowledge, the first inversion-recovery measurements on such systems. The suitability of this approach for gaining insights into the nature of metal ion binding sites in large metalloproteins is critically assessed.