Using iodide single-wavelength anomalous dispersion, we report the first structural characterization of TphB to 1.85 angstrom resolution. Contrary to prior speculations, a fluorescent scan unambiguously shows that TphB coordinates Zn2+ and not Fe2+. The molecular architecture of TphB provides a rationale to the primary-level divergence observed between TphB and other cis-dihydrodiol dehydrogenases while explaining its intriguingly close evolutionary clustering check details with non-dihydrodiol dehydrogenases belonging to the isocitrate/iso-propylmalate family of enzymes. Sequence and structural analyses reveal a putative substrate-binding pocket proximal to the bound Zn2+. In silico
substrate modeling in this putative binding pocket suggests a mechanistic sequence relying on H291, K295, and Zn2+ as core mediators of catalytic turnover. Overall, this study reveals novel Quizartinib concentration structural and mechanistic insights into a decarboxylating cis-dihydrodiol dehydrogenase that mediates one of the two catalytic steps in the
biodegradation of the environmental pollutant Tph. (c) 2012 Elsevier Ltd. All rights reserved.”
“Stretching frequencies of acyl groups of stabilized triphenyl phosphonium ylides with ester, keto or cyano groups depend in part on the orientations of the acyl groups, syn or anti, with respect to phosphorus. Frequencies predicted by ab initio HF methods are higher than observed, and for diesters and diketones are higher for anti than syn acyl groups. For diester and diketo ylides and their cyano derivatives a Scale Factor, SF, of 0.866, fits much of the data with HF/6-31G(d) calculations, although it is lower than the literature value. The literature SF values see more for DFT methods, e.g., BLYP/6-31G(d) and B3LYP/6-31G(d), are closer to unity, and agreement with experiment is reasonable, except that for mixed anti isopropyloxy or t-butyloxy and syn methoxy or ethoxy diester ylides predicted stretching frequencies of the syn acyl groups by BLYP are too low, and fits are worse than with HF/6-31G(d), but B3LYP gives
satisfactory results. The combination of ab initio methods and determination of IR acyl stretching frequencies may be useful when structure determination of stabilized ester, keto and cyano ylides by X-ray crystallography is not feasible, or when con former interconversion in solution is too fast for use of NMR spectroscopy. (c) 2008 Elsevier B.V. All rights reserved.”
“We report here on a case of a 27-year-old man with atypical hemolytic uremic syndrome and diffuse alveolar hemorrhage associated with influenza A H1N1 infection. Treatment with oseltamivir, plasma exchange and hemodiafiltration for the hemolytic uremic syndrome and meticulous supportive care with steroid pulse therapy for the pulmonary alveolar hemorrhage was successful in this case.