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Resistance to beta-lactam antibiotics mediated by metallo-beta-lactamases (MBLs) is a growing problem. We describe the use of protein-observe 19F-NMR (PrOF NMR) to study the dynamics of the São Paulo MBL (SPM-1) from beta-lactam- resistant Pseudomonas aeruginosa. Cysteinyl variants on the a3 and L3 regions, which flank the di-ZnII active site, were selectively 19F-labeled using 3-bromo-1,1,1-trifluoroacetone. The PrOF NMR results reveal roles for the mobile a3 and L3 regions in the binding of both inhibitors and hydrolyzed beta-lactam products to SPM-1. These results have implications for the mechanisms and inhibition of MBLs by beta-lactams and non-beta-lactams and illustrate the utility of PrOF NMR for efficiently analyzing metal chelation, identifying new binding modes, and studying protein binding from a mixture of equilibrating isomers.

γ-Butyrobetaine hydroxylase (BBOX) is a 2-oxoglutarate dependent oxygenase that catalyzes the final hydroxylation step in the biosynthesis of carnitine. BBOX was shown to catalyze the oxidative desymmetrization of achiral N,N-dialkyl piperidine-4-carboxylates to give products with two or three stereogenic centers.

A temperature-dependent relay of chirality is based on the inversion of the nitrogen lone pair in cyclic azasugars. Elimination from the conformation preferred at a given temperature leads to a cyclic imine, and in a subsequent nucleophilic attack the stereochemical information is relayed.

An approach to the indirect measurement of nuclear spin relaxation rates of low-magnetogyric ratio (γ) nuclei using the process of satellite exchange is described. The method does not require the observation of, or even the ability to provide radio-frequency pulses to, the low-γ nucleus, but requires this to be scalar coupled to an NMR observable nucleus, such as 31 P or 1 H, making it especially attractive for the study of diamagnetic transition metals. In situations where spin relaxation is dominated by chemical shift anisotropy (CSA), the determination of the longitudinal spin relaxation time constant (T1 ) of the metal becomes possible, as illustrated for 195 Pt and 107/109 Ag.