We have prepared Lactobacillus casei
dihydrofolate reductase containing biosynthetically
incorporated
(2S,4S)-5-fluoroleucine ([5-F]-Leu DHFR) and
have obtained its 1H and 19F NMR spectra at 9.4
Tesla. The 19F
spectrum of [5-F]-Leu DHFR showed 12 fairly sharp peaks (one
containing two overlapped signals) for the 13
leucine residues in DHFR, covering a chemical shift range of 15 ppm.
The large range of chemical shifts observed
could not be explained solely in terms of the electrostatic field
effects due to local charge fields and is thought to
have a second contribution from side-chain conformational differences
(γ-gauche effects) between different leucine
residues, making 19F NMR of aliphatic amino acids in
proteins a potentially useful new probe of protein
structure.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.