Efficient ensemble and IDA system based on the metal binding motif for highly sensitive and selective detection and determination of carbonate and citrate ions

Label-free fluorescent ionic liquid-functionalized silicon nanoparticles with tunable amphiphilicity for highly sensitive and selective detection of Hg2+ were synthesized.

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Efficient Ensemble System Based on the Copper Binding Motif for Highly Sensitive and Selective Detection of Cyanide Ions in 100% Aqueous Solutions by Fluorescent and Colorimetric Changes

Analytical Chemistry ◽

10.1021/acs.analchem.5b01982 ◽

2015 ◽

Vol 87 (18) ◽

pp. 9308-9314 ◽

Cited By ~ 63

Author(s):

Kwan Ho Jung ◽

Keun-Hyeung Lee

Keyword(s):

Aqueous Solutions ◽

Binding Motif ◽

Selective Detection ◽

Copper Binding ◽

Highly Sensitive

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Conformational changes in CLIP-170 regulate its binding to microtubules and dynactin localization

The Journal of Cell Biology ◽

10.1083/jcb.200402082 ◽

2004 ◽

Vol 166 (7) ◽

pp. 1003-1014 ◽

Cited By ~ 124

Author(s):

Gideon Lansbergen ◽

Yulia Komarova ◽

Mauro Modesti ◽

Claire Wyman ◽

Casper C. Hoogenraad ◽

...

Keyword(s):

Conformational Changes ◽

Metal Binding ◽

Intramolecular Interaction ◽

Resonance Energy Transfer ◽

Resonance Energy ◽

Scanning Force Microscopy ◽

Binding Motif ◽

Force Microscopy ◽

Scanning Force ◽

Metal Binding Motif

Cytoplasmic linker protein (CLIP)-170, CLIP-115, and the dynactin subunit p150Glued are structurally related proteins, which associate specifically with the ends of growing microtubules (MTs). Here, we show that down-regulation of CLIP-170 by RNA interference results in a strongly reduced accumulation of dynactin at the MT tips. The NH2 terminus of p150Glued binds directly to the COOH terminus of CLIP-170 through its second metal-binding motif. p150Glued and LIS1, a dynein-associating protein, compete for the interaction with the CLIP-170 COOH terminus, suggesting that LIS1 can act to release dynactin from the MT tips. We also show that the NH2-terminal part of CLIP-170 itself associates with the CLIP-170 COOH terminus through its first metal-binding motif. By using scanning force microscopy and fluorescence resonance energy transfer-based experiments we provide evidence for an intramolecular interaction between the NH2 and COOH termini of CLIP-170. This interaction interferes with the binding of the CLIP-170 to MTs. We propose that conformational changes in CLIP-170 are important for binding to dynactin, LIS1, and the MT tips.

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Characterization of the phenylurea hydrolases A and B: founding members of a novel amidohydrolase subgroup

Biochemical Journal ◽

10.1042/bj20081488 ◽

2009 ◽

Vol 418 (2) ◽

pp. 431-441 ◽

Cited By ~ 43

Author(s):

Jeevan L. Khurana ◽

Colin J. Jackson ◽

Colin Scott ◽

Gunjan Pandey ◽

Irene Horne ◽

...

Keyword(s):

Metal Binding ◽

Catalytic Mechanism ◽

Binding Motif ◽

Evolutionary Origins ◽

Effects Of Temperature ◽

Amidohydrolase Superfamily ◽

Challenging Question ◽

Active Site Sequence

Mycobacterium brisbanense strain JK1, a bacterium capable of degrading the herbicide diuron, was isolated from herbicide-exposed soil. A gene/enzyme system with diuron hydrolase activity was isolated from this strain and named PUH (phenylurea hydrolase) B (puhB/PuhB) because of its close similarity to the previously characterized PUH A (puhA/PuhA). Both PUHs were heterologously expressed, purified and characterized. The PUHs were found to oligomerize as hexamers in solution, with each monomer containing a mononuclear Zn2+ active site. Sequence analysis showed that these enzymes belong to the metal-dependent amidohydrolase superfamily, although they contain a hitherto unreported Asn-X-His metal-binding motif and appear to form a novel sub-group within this superfamily. The effects of temperature and solvent on the enzymes were characterized. Determination of the kinetic parameters of the PUHs was used alongside Brønsted plots to develop a plausible catalytic mechanism, which is similar to that used by urease. In addition to the primary PUH activity, both enzymes are catalytically promiscuous, efficiently hydrolysing esters, carbamates and phosphotriesters. In fact, an analogue of diuron, in which the C–N bond was replaced by a C–O bond, was found to be turned over as efficiently as diuron, suggesting that the substrate specificity is predominantly determined by steric factors. The discovery of PuhA and PuhB on separate continents, and the absence of any other close homologues in the available sequence databases, poses a challenging question regarding the evolutionary origins of these enzymes.

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