Inhibitors of Bacterial Nitric Oxide Synthase, and Related Screening Methods
申请人:Lippard Stephen J.
公开号:US20110201042A1
公开(公告)日:2011-08-18
The invention relates in part to compounds that act as highly nitric oxide (NO)-specific turn-on fluorescent probes. The present invention also relates to the use of these fluorescein-based sensors to screen selectively for inhibitors of bacterial nitric oxide synthase (bNOS). Compounds of the present invention readily detect nitric oxide produced in vivo. Therefore they can be used in an assay that measures NO production by bNOS. Using a sensor of the invention one can screen libraries of small molecules for inhibitors of bNOS.
Mechanism of Nitric Oxide Reactivity and Fluorescence Enhancement of the NO-Specific Probe CuFL1
作者:Lindsey E. McQuade、Michael D. Pluth、Stephen J. Lippard
DOI:10.1021/ic101054u
日期:2010.9.6
The mechanism of the reaction of CuFL1 (FL1 = 2-2-chloro-6-hydroxy-5-[(2-methylquinolin-8-ylamino)methyl]-3-oxo-3H-xanthen-9-yl}benzoic acid) with nitric oxide (NO) to form the N-nitrosated product FL1-NO in buffered aqueous solutions was investigated. The reaction is first-order in [CuFL1], [NO], and [OH-]. The observed rate saturation at high base concentrations is consistent with a mechanism in which the protonation state of the secondary amine of the ligand is important for reactivity. This information provides a rationale for designing faster-reacting probes by lowering the pk(a) of the secondary amine. Activation parameters for the reaction of CuFL1 with NO indicate an associative mechanism (Delta S-double dagger = -120 +/- 10 J/mol.K) with a modest thermal barrier (Delta H-double dagger = 41 +/- 2 kJ/mol; E-a = 43 +/- 2 kJ/mol). Variable-pH electron paramagnetic resonance experiments reveal that, as the secondary amine of CuFL1 is deprotonated, electron density shifts to yield a new spin-active species having electron density localized on the deprotonated amine nitrogen atom. This result suggests that FL1-NO formation occurs when NO attacks the deprotonated secondary amine of the coordinated ligand, followed by inner-sphere electron transfer to Cu(II) to form Cu(I) and release of FL1-NO from the metal.
FLUORESCEIN BASED SENSORS FOR TRACKING NITRIC OXIDE IN LIVE CELLS
申请人:Lippard Stephen J.
公开号:US20090017552A1
公开(公告)日:2009-01-15
The present invention is directed, in part, to coordination complexes for detecting analytes, and methods of making and using the same.