We studied the effect of pH on ligand binding in wild-type lactose permease or mutants in the four residues-Glu-269, Arg-302, His-322, and Glu-325-that are the key participants in H(+) translocation and coupling between sugar and H(+) translocation. Although wild-type permease or mutants in Glu-325 and Arg-302 exhibit marked decreases in affinity at alkaline pH, mutants in either His-322 or Glu...

Fluence response relationships for the induction of DNA damage in the skin of UV-irradiated Xiphophorus fish were obtained by quantitative gel electrophoresis of unlabeled DNA following extraction and treatment with an enzyme preparation that makes single strand breaks next to cyclobutane pyrimidine dimers. A buffer containing 7 M urea minimized the degradation of DNA during extraction and gave...

Signalling interplay between transforming growth factor-β (TGFβ) and CCN2 [also called connective tissue growth factor (CTGF)] plays a crucial role in the progression of diabetic nephropathy and has been implicated in cellular differentiation. To investigate the potential role of microRNAs (miRNAs) in the mediation of this signalling network, we performed miRNA screening in mesangial cells trea...

4-trans-(NN-Dimethylamino)cinnamaldehyde (an aldehyde, DACA) and 4-trans-(NN-dimethylamino)cinnamoylimidazole (an amide, DACI) have been shown to be substrates for human aldehyde dehydrogenase (EC 1.2.1.3) which form chromophoric covalent intermediates. The spectra of covalent intermediates from both the cytoplasmic (E1) and mitochondrial (E2) isoenzymes derived from DACA and DACI were compared...

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Previous reports have suggested that the hypoxic microenvironment provides a niche that supports tumor stem cells, and that this might explain clinical observations linking hypoxia to metastasis. To test this, we examined the effects of a hypoxia-activated prodrug, TH-302, on the tumor-initiating cell (TIC) frequency of patient-derived pancreatic xenografts (PDX).The frequencies of TIC, measure...

XTE J1739–302 is a transient X-ray source with unusually short outbursts, lasting on the order of hours. Here we give a summary of X-ray observations we have made of this object in outburst with the Rossi X-ray Timing Explorer (RXTE) and at a low level of activity with the Chandra X-ray Observatory, as well as observations made by other groups. Visible and infrared spectroscopy of the mass dono...

www.sciencemag.org (this information is current as of November 28, 2006 ): The following resources related to this article are available online at http://www.sciencemag.org/cgi/content/full/302/5644/449 version of this article at: including high-resolution figures, can be found in the online Updated information and services, http://www.sciencemag.org/cgi/content/full/302/5644/449/DC1 can be fou...