Hereditary Spastic Paraplegia Protein Spartin Is an FK506-Binding Protein Identified by mRNA Display

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Copper mediated defluorinative allylic alkylation of difluorohomoallyl alcohol derivatives directed to an efficient synthetic method for (Z)-fluoroalkene dipeptide isosteres

Difluoroallylation of optically pure O-silylated (S)-2-methyl-3-hydroxypropanal 10a with bromodifluoropropene mediated by indium provided the corresponding difluorohomoallyl alcohol 11a with low diastereoselectivity, but without a decrease in optical purity. Defluorinative allylic alkylation of each diastereomer of the difluorohomoallyl alcohol efficiently proceeded by the reaction with trialkylaluminium and Cu(I) system or Grignard reagent and a catalytic amount of CuI system in THF to give the fluorine-substituted allylic alcohol 12 in an high yield and in an excellent Z selective manner. Subsequent imidate Claisen rearrangement of the allylic alcohol 12 proceeded with a complete 1,3-chirality transfer to give the fluoroalkene dipeptide isostere structure 14 after the final conversion of the primary alcohol 20 into the carboxylic acid form.     

Isolation and characterization of atropisomers of seven-membered-ring benzolactams

The atropisomeric properties of seven-membered-ring benzolactams (7a-c and 8a) [1,5-benzodiazepin-2-one (a), 1,5-benzothiazepin-4-one (b), and 1-benzazepin-2-one (c)] were examined. The atropisomers were isolated as the diastereomers with an (S)-phenethylamide moiety, which were characterized by X-ray crystallography, and the barriers to their interconversion were clarified.     

Intra Q-body: an antibody-based fluorogenic probe for intracellular proteins that allows live cell imaging and sorting

Although intracellular biomarkers can be imaged with fluorescent dye(s)-labeled antibodies, the use of such probes for precise imaging of intracellular biomarkers in living cells remains challenging due to background noise from unbound probes. Herein, we describe the development of a conditionally active Fab-type Quenchbody (Q-body) probe derived from a monoclonal antibody (DO-1) with the ability to both target and spatiotemporally visualize intracellular p53 in living cells with low background signal. p53 is a key tumor suppressor and validated biomarker for cancer diagnostics and therapeutics. The Q-body displayed up to 27-fold p53 level-dependent fluorescence enhancement in vitro with a limit of detection of 0.72 nM. In fixed and live cells, 8.3- and 8.4-fold enhancement was respectively observed. Furthermore, we demonstrate live-cell sorting based on p53 expression. This study provides the first evidence of the feasibility and applicability of Q-body probes for the live-cell imaging of intrinsically intracellular proteins and opens a novel avenue for research and diagnostic applications on intracellular target-based live-cell sorting.

A fluorescent immunosensor that lights up tumor biomarker p53 in living cells was developed based on the Q-body technology. The technology was further applied to the live cell monitoring of p53 levels, and live cell sorting based on p53 expression.     

Synthesis of β‐monosubstituted α,β‐unsaturated amides with Z‐selectivity using diphenylphosphonoacetamides

The utility of diphenylphosphonoacetamides [(PhO)₂P(O)CH₂CONRR′] as Horner–Wadsworth–Emmons reagents was examined with five different patterns of substitution upon the amide nitrogen atom ( 2a : R, R′ = CH₂Ph; 2b : R = CH₂Ph, R′ = H; 2c : R = Me, R′ = OMe; 2d : R, R′ = Ph; 2e : R, R′ = (CH₂)₄). The reaction of 2a was found to be Z‐selective for aromatic aldehydes with selectivities up to 95:5. Reagent 2b led to reasonable selectivity for both benzaldehyde (85:15) and 3‐phenylpropionaldehyde (87:13), while 2c was somewhat effective for only the latter alkyl aldehyde (83:17). Compounds 2d and 2e exhibited slightly lower selectivities compared with 2a . © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:515–523, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20054