Single-molecule imaging of a fluorescent unnatural amino acid incorporated into nicotinic receptors.

ABSTRACT: We report on the first, to our knowledge, successful detection of a fluorescent unnatural amino acid (fUAA), Lys(BODIPYFL), incorporated into a membrane protein (the muscle nicotinic acetylcholine receptor, nAChR) in a living cell. Xenopus oocytes were injected with a frameshift-suppressor tRNA, amino-acylated with Lys(BODIPYFL) and nAChR (alpha/beta19'GGGU/gamma/delta) mRNAs. We measured fluorescence from oocytes expressing nAChR beta19'Lys(BODIPYFL), using time-resolved total internal reflection fluorescence microscopy. Under conditions of relatively low receptor density (<0.1 receptors/microm(2)), we observed puncta with diffraction-limited profiles that were consistent with the point-spread function of our microscope. Furthermore, diffraction-limited puncta displayed step decreases in

SUBMITTER: Pantoja R 

PROVIDER: S-EPMC2710013 | biostudies-literature | 2009 Jan

REPOSITORIES: biostudies-literature