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71.
Eight cholesterol based cationic lipids differing in the headgroup have been synthesized based on the ether linkage between the cationic headgroup and the cholesterol backbone. All the lipids formed stable suspensions in water. Transfection efficacies were examined in the absence and presence of serum using their optimized liposomal (lipid:DOPE) formulations. Our results showed that the transfection activities depend on the nature of the headgroup. Lipid bearing 4-N,N′-dimethylaminopyridine (DMAP) as headgroup showed the maximum transfection efficacy in the presence of serum. Importantly, the optimized formulation for this cationic lipid does not require DOPE, which is being used by most commercially available formulations. Cytotoxicity studies showed that the introduction of the positive charge decreases the cell viability of the cationic lipid formulations. Gel electrophoresis and Ethidium bromide exclusion assay revealed the different DNA binding abilities of formulations depending upon the headgroup of the cholesteryl lipid. 相似文献
72.
Neil A. Koorbanally Neil R. Crouch Avinash Harilal Bavani Pillay Dulcie A. Mulholland 《Biochemical Systematics and Ecology》2006
We report on the first phytochemical investigation of a member of the African genus Resnova (Hyacinthoideae: Hyacinthaceae). From the dichloromethane extract of the bulbs of both Resnova humifusa and Eucomis montana (Hyacinthoideae: Hyacinthaceae) a novel 3-benzyl-4-chromanone homoisoflavonoid, 5,6-dimethoxy-7-hydroxy-3-(4′-hydroxybenzyl)-4-chromanone, was isolated. A further 11 known homoisoflavonoids were also identified, the 12 in total presenting a clear biosynthetic sequence. Eight of the 12 compounds found were common to both species. 相似文献
73.
Michael C. Mullenix Pravin T. P. Kaumaya Richard F. Mortensen 《Journal of cellular biochemistry》1994,54(3):343-353
Human C-reactive protein (CRP) is an acute phase blood component that accumulates at sites of tissue damage and necrosis and is degraded by neutrophils to biologically active peptides. A dodecapeptide composed of amino acids 27–38 of CRP mediates cell attachment in vitro. This peptide was designated the cell-binding peptide (CB-Pep) of CRP. Characterization of the interaction between fibroblasts and modified synthetic peptides with sequential deletions from either the N-terminus or C-terminus revealed that the minimal sequence for cell attachment or inhibition of cell attachment to the CB-Pep was Phe-Thr-Val-Cys-Leu , which corresponds to residues 33–37 within each of the five 206 amino acid subunits of CRP. The pentapeptide by itself mediated cell attachment. Substitutions for each residue within the CB-Pep indicated that the critical residues for activity were Phe-33 and Thr-34. This cell-binding pentapeptide represents a recognition motif for cell adhesion not found in other proteins. 相似文献
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Marc Kschonsak Lionel Rougé Christopher P. Arthur Ho Hoangdung Nidhi Patel Ingrid Kim Matthew C. Johnson Edward Kraft Alexis L. Rohou Avinash Gill Nadia Martinez-Martin Jian Payandeh Claudio Ciferri 《Cell》2021,184(5):1232-1244.e16
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76.
Avinash S. Punekar Tyson R. Shepherd Josefine Liljeruhm Anthony C. Forster Maria Selmer 《Nucleic acids research》2012,40(20):10507-10520
RlmM (YgdE) catalyzes the S-adenosyl methionine (AdoMet)-dependent 2′O methylation of C2498 in 23S ribosomal RNA (rRNA) of Escherichia coli. Previous experiments have shown that RlmM is active on 23S rRNA from an RlmM knockout strain but not on mature 50S subunits from the same strain. Here, we demonstrate RlmM methyltransferase (MTase) activity on in vitro transcribed 23S rRNA and its domain V. We have solved crystal structures of E. coli RlmM at 1.9 Å resolution and of an RlmM–AdoMet complex at 2.6 Å resolution. RlmM consists of an N-terminal THUMP domain and a C-terminal catalytic Rossmann-like fold MTase domain in a novel arrangement. The catalytic domain of RlmM is closely related to YiiB, TlyA and fibrillarins, with the second K of the catalytic tetrad KDKE shifted by two residues at the C-terminal end of a beta strand compared with most 2′O MTases. The AdoMet-binding site is open and shallow, suggesting that RNA substrate binding may be required to form a conformation needed for catalysis. A continuous surface of conserved positive charge indicates that RlmM uses one side of the two domains and the inter-domain linker to recognize its RNA substrate. 相似文献
77.
Matthew C. Lucas David S. Carter Hai-Ying Cai Eun Kyung Lee Ryan C. Schoenfeld Sandra Steiner Marzia Villa Robert J. Weikert Pravin S. Iyer 《Bioorganic & medicinal chemistry letters》2009,19(16):4630-4633
A variety of novel aminoheterocycle scaffolds as selective monoamine reuptake inhibitors have been prepared and one of these scaffolds is achiral. The main elements responsible for hERG channel, CYP2D6 and CYP3A4 inhibition were identified. 相似文献
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Venkat R. Gadhachanda Kyle J. Eastman Qiuping Wang Avinash S. Phadke Dharaben Patel Wengang Yang Christopher W. Marlor Milind Deshpande Mingjun Huang Jason A. Wiles 《Bioorganic & medicinal chemistry letters》2018,28(21):3463-3471
An unprecedented series of organometallic HCV (hepatitis C virus) NS5A (nonstructural 5A protein) replication complex inhibitors that incorporates a 1,1′-ferrocenediyl scaffold was explored. This scaffold introduces the elements of linear flexibility and non-planar topology that are unconventional for this class of inhibitors. Data from 2-D NMR spectroscopic analyses of these complexes in solution support an anti (unstacked) arrangement of the pharmacophoric groups. Several complexes demonstrate single-digit picomolar in vitro activity in an HCV genotype-1b replicon system. One complex to arise from this investigation (10a) exhibits exceptional picomolar activity against HCV genotype 1a and 1b replicons, low hepatocellular cytotoxicity, and good pharmacokinetic properties in rat. 相似文献