Project description:Aristolochic acid nephropathy (AAN) is characterised by rapidly progressive tubulointerstitial nephritis culminating in end stage renal failure and urothelial malignancy. microRNAs (miRs) are small endogenous post-transcriptional regulators of gene expression implicated in numerous physiological and pathological processes. We aimed to characterise the mechanism of AA induced cell cycle arrest and its regulation by miRs. The microarray experiment was performed to identify differentially regulated microRNAs in human proximal tubulal epithelial cells treated with aristolochic acid (AA).
Project description:The last two decades have seen the rise of antimicrobial peptides (AMPs) to combat emerging antibiotic resistance. Herein we report the solid-phase synthesis of short lipidated ?/?-AA hybrid peptides. This family of lipo-chimeric peptidomimetics displays potent and broad-spectrum antimicrobial activity against a range of multi-drug resistant Gram-positive and Gram-negative bacteria. These lipo-?/?-AA hybrid peptides also demonstrate high biological specificity, with no hemolytic activity towards red blood cells. Fluorescence microscopy suggests that these lipo-?/?-AA chimeric peptides can mimic the mode of action of AMPs and kill bacterial pathogens via membrane disintegration. As the composition of these chimeric peptides is simple, therapeutic development could be economically feasible and amenable for a variety of antimicrobial applications.
Project description:A cytochrome in an extremely halophilic archaeon, Haloferax volcanii, was purified to homogeneity. This protein displayed a redox difference spectrum that is characteristic of a-type cytochromes and a CN(-) complex spectrum that indicates the presence of heme a and heme a(3). This cytochrome aa(3) consisted of 44- and 35-kDa subunits. The amino acid sequence of the 44-kDa subunit was similar to that of the heme-copper oxidase subunit I, and critical amino acid residues for metal binding, such as histidines, were highly conserved. The reduced cytochrome c partially purified from the bacterial membrane fraction was oxidized by the cytochrome aa(3), providing physiological evidence for electron transfer from cytochrome c to cytochrome aa(3) in archaea.