Plasmodium falciparum ferredoxin-NADP+ reductase (FNR) is a FAD-containing enzyme that, in addition to be a promising target of novel antimalarial drugs, represents an excellent model of plant-type FNRs. The cofactor specificity of FNRs depends on differences in both kcat and Km values for NADPH and NADH. Here, we report that deletion of the hydroxyl group of the conserved Y258 of P. falciparum FNR, which interacts with the 2′-phosphate group of NADPH, selectively decreased the kcat of the NADPH-dependent reaction by a factor of 2 to match that of the NADH-dependent one. Rapid-reaction kinetics, active-site titrations with NADP+, and anaerobic photoreduction experiments indicated that this effect may be the consequence of destabilization of the catalytically competent conformation of bound NADPH. Moreover, because the Y258F replacement increased the Km for NADPH 4-fold and decreased that for NADH 3-fold, it led to a drop in the ability of the enzyme to discriminate between the coenzymes from 70- to just 1...
Sara Baroni; Vittorio Pandini; Maria Antonietta Vanoni; Alessandro Aliverti
The two enantiomers of 2-(2-hydroxybiphenyl-4-yl)propanoic acid ((S)- and (R)-BPOH) have been selected as probes for human serum albumin (HSA). Photophysical characterization in the absence of protein led to emission maxima, singlet energies, quantum yields, and fluorescence lifetime values ... more
The photodissociation of H2O in its B band is a prototype for nonadiabatic reaction dynamics. In addition to dissociation via the adiabatic pathway to the OH(Ã2Σ+) + H fragments, it also produces the OH(X̃2Π) + H fragments through two nonadiabatic pathways: the B̃ → X̃ transition via two co ... more
Due to the widespread occurrence in the environment and potential risk toward organisms of fluoroquinolones (FQs), it is of importance to develop high efficient methods for assessing their occurrence and environmental risk. A monoclonal antibody (Mab) with broad cross-reactivity to FQs was ... more
Rohm and Haas Powder Coatings is delighted to announce that its Reading, Pennsylvania, facility is the first site in the world to receive the RCMS® Site Certification awarded by the American Chemical Council (ACC).
When Raj Gupta, Chairman and CEO of Rohm and Haas Company, became Chairman ... more