Hyperpolarization of nuclear spins through techniques such as dynamic nuclear polarization (DNP) can greatly increase the signal-to-noise ratio in NMR measurements, thus eliminating the need for signal averaging. This enables the study of many dynamic processes which would otherwise not be amenable to study by NMR spectroscopy. A report of solid- to liquid-state DNP of a short peptide, bacitracin A, as well as of a full-length protein, L23, is presented here. The polypeptides are hyperpolarized at low temperature and dissolved for NMR signal acquisition in the liquid state in mixtures of organic solvent and water. Signal enhancements of 300-2000 are obtained in partially deuterated polypeptide when hyperpolarized on (13)C and of 30-180 when hyperpolarized on (1)H. A simulated spectrum is used to identify different resonances in the hyperpolarized (13)C spectra, and the relation between observed signal enhancement for various groups in the protein and relaxation parameters measured from the hyperpolarized samples is discussed. Thus far, solid- to liquid-state DNP has been used in conjunction with small molecules. The results presented here, however, demonstrate the feasibility of hyperpolarizing larger proteins, with potential applications toward the study of protein folding or macromolecular interactions.

A series of alumina-supported alkaline earth metal oxide catalysts were prepared by recipient-wetness impregnation. These catalysts were characterized by nitrogen-sorption to determine their surface areas and pore size distributions. The basicities of these catalysts were characterized by temperature-programmed des0rption of carbon dioxide. The TPD results demonstrate that all of the catalysts have one-peak profiles. The basicity increases with increasing atomic number of the alkaline earth metal. The alumina-supported alkaline earth oxides exhibit the same basic properties as bulk metal oxides. However, the presence of alumina can increase the mechanical strength of the catalyst, since the alkaline earth oxides have a weak mechanical strength. The basic properties of the catalysts are strongly influenced by the calcination temperature.

Time resolved metal line profile by near-ultraviolet tunable diode laser absorption spectroscopyA setup for measuring femtosecond transient absorption in the gas phase is reported. The apparatus is based on a 1 kHz amplified Ti:sapphire laser system and measures gas-phase transient absorption using a shot-to-shot normalization scheme with background subtraction. We have used this setup to examine the wave packet dynamics of the I 2 B state in the vapor phase as a benchmark. The results are consistent with those reported by other groups using indirect transient absorption techniques.