Diverse organophosphate hydrolases have convergently evolved the ability to hydrolyse man-made organophosphates. Thus, these enzymes are attractive model systems for studying the factors shaping enzyme functional evolution. Methyl parathion hydrolase (MPH) is an enzyme from the metallo-β-lactamase superfamily, which hydrolyses a wide range of organophosphate, aryl ester and lactone substrates. ...

[graph: see text] 8-Hydroxyquinoline benzoates were developed as a new set of 8-HQ derivatives for highly sensitive fluorescent chemosensors for transition metal ions. A prominent fluorescence enhancement was found in the presence of transition metal ions such as Hg2+ and Cu2+, and this was suggested to result from the suppression of radiationless transitions from the npi state in the chemosens...

Using UV-vis spectrophotometic method, the formation constants for interaction of Cd2+(aq) andCo2+(aq) ions with L-Alanine were experimentally studied at pH = 4.1 ± 0.01 (50mM of potassiumhydrogen phthalate buffer), ionic strength of 0.1M potassium nitrate and at 5 differenttemperatures 15,20, 25,30 and 35°C. The optical absorption spectra of mixtures containingconsidered cations and L-Alanine ...

Transition metals traditionally have been ignored in chemical models of interstellar clouds. Thermochemical considerations indicate that the formation of several important species can be catalyzed by transition metal ions. The importance of such chemistry depends critically upon the rate of conversion of atomic metal ions into molecular species. Potential energy curves and transition moments ha...

This paper describes a sensor employing a gel formed from an interpenetrating polymer network of poly(vinyl alcohol) and a copolymer of N-isopropylacrylamide and acrylic acid. This gel exhibits a continuous volume-phase transition that is strongly dependent on the presence of polyvalent metal ions in the gel solvent. A sensor apparatus has been constructed that estimates, in real time, the tran...

Many fluorescent proteins have been created to act as genetically encoded biosensors. With these sensors, changes in fluorescence report on chemical states in living cells. Transition metal ions such as copper, nickel, and zinc are crucial in many physiological and pathophysiological pathways. Here, we engineered a spectral series of optimized transition metal ion-binding fluorescent proteins t...

A series of metal-organic frameworks representing a non-interpenetrated framework analogue of MOF-14 have been synthesized by using two different linkers, 4,4',4''-benzene-1,3,5-triyl-benzoic acid (H(3)BTB) and 4,4'-bipyridine (Bpy). Interestingly, the transition metal ions in the paddle-wheel metal clusters could be exchanged by other transition metal ions via a direct single-crystal to single...

A group of highly efficient Zn(II)-dependent RNA-cleaving deoxyribozymes has been obtained through in vitro selection. They share a common motif with the '8-17' deoxyribozyme isolated under different conditions, including different design of the random pool and metal ion cofactor. We found that this commonly selected motif can efficiently cleave both RNA and DNA/RNA chimeric substrates. It can ...