Performance tuning non-uniform sampling for sensitivity enhancement of signal-limited biological NMR.

Non-uniform sampling (NUS) has been established as a route to obtaining true sensitivity enhancements when recording indirect dimensions of decaying signals in the same total experimental time as traditional uniform incrementation of the indirect evolution period. Theory and experiments have shown that NUS can yield up to two-fold improvements in the intrinsic signal-to-noise ratio (SNR) of each dimension, while even conservative protocols can yield 20-40% improvements in the intrinsic SNR of NMR data. Applications of biological NMR that can benefit from these improvements are emerging, and in this work we develop some practical aspects of applying NUS nD-NMR to studies that approach the traditional detection limit of nD-NMR spectroscopy.

Thermodynamic analysis and fluorescence imaging of homochiral amino acid-amino acid interactions at the air/water interface.

Surface pressure-molecular area (Π-A) isotherms and fluorescence microscopy were used to investigate the interactions between N-stearoyl-glutamic acid (l- and d-) and l-arginine at the air/water interface. N-stearoyl-glutamic acids (C18-Glu) with different chirality (l- and d-) were spread at the air-water interface onto subphases containing varied concentrations of l-arginine at pH 5. The apparent binding affinity of C18-Glu to l-arginine was obtained by fitting the plots of the change in mean molecular area of C18-Glu vs.