Evidence for the detachment of a ribonucleoprotein messenger complex from EDTA-treated rabbit reticulocyte polyribosomes

A ribonucleoprotein complex can be released from rabbit reticulocyte polyribosomes by EDTA treatment. It contains a 9-S RNA which is presumably the messenger for hemoglobin. This complex is retained on nitrocellulose filters, whereas free RNA as well as the pronase-treated complex are not. Its protein moiety can be labelled with [14C]-iodoacetic acid. © 1969.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Selective monoalkylation of amines with lightelectrophiles using a flow microreactor system

International audienceThe challenging direct monoalkylation of amines with light electrophilic reagents (C1 to C3) was performed through a flow microreactor approach. The efficiency of mixing coupled with short residence times (tR = 0.7–62 s) allows the transfer of a single alkyl group from R-OTf onto primary amines (R = Et, Pr) as well as on secondary amines (R = Me, Et, Pr, allyl, propargyl) with good selectivities

Formylation of amines through catalyst- and solvent-free transamidation reaction

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Selective monomethylation of primary amines with simple electrophiles.

International audienceDirect monomethylation of primary amines with methyl triflate was achieved with high selectivity (up to 96%). The key point of this single methyl transfer stems from the use of HFIP as the solvent that interferes with amines and avoids overmethylation

Evolution of the Polyribosome Distribution during in vivo Reticulocyte Maturation

Maturation of rabbit reticulocytes in vivo is accompanied by a shift in the polyribosome distribution from heavy to small clusters. Copyright © 1970, Wiley Blackwell. All rights reservedSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Characterization of the Messenger Ribonucleoprotein Released from Reticulocyte Polyribosomes by EDTA Treatment

When reticulocyte polyribosomes are dissociated by EDTA treatment, two ribonucleoproteins are released: one of these, messenger ribonucleoprotein, contains the messenger RNA for globin chains and two heavy proteins (molecular weights 130 000 and 68 000); the other contains the 5 S ribosomal RNA and a lighter protein (molecular weight 45000). The protein moiety of the messenger ribonucleoprotein is required for the binding of the mRNA to deoxycholate‐washed native 40 S ribosomal subunits. Copyright © 1971, Wiley Blackwell. All rights reservedSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Cationic phosphoramidate α-oligonucleotides efficiently target single-stranded DNA and RNA and inhibit hepatitis C virus IRES-mediated translation

A potential means to improve the efficacy of steric-blocking antisense oligonucleotides (ON) is to increase their affinity for a target RNA. The grafting of cationic amino groups to the backbone of the ON is one way to achieve this, as it reduces the electrostatic repulsion between the ON and its target. We have examined the duplex stabilising effects of introducing cationic phosphoramidate internucleoside linkages into ON with a non-natural α-anomeric configuration. Cationic α-ON bound with high affinity to single-stranded DNA and RNA targets. Duplex stabilisation was proportional to the number of cationic modifications, with fully cationic ON having particularly high thermal stability. The average stabilisation was greatly increased at low ionic strength. The duplex formed between cationic α-ON and their RNA targets were not substrates for RNase H. The penalty in T(m) inflicted by a single mismatch, however, was high; suggesting that they are well suited as sequence-specific, steric-blocking, antisense agents. Using a well-described target sequence in the internal ribosome entry site of the human hepatitis C virus, we have confirmed this potential in a cell-free translation assay as well as in a whole cell assay. Interestingly, no vectorisation was necessary for the cationic α-ON in cell culture

Toward high yield synthesis of peptide–oligonucleotide chimera through a disulfide bridge: A simplified method for oligonucleotide activation.

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Bromine-lithium exchange on gem-dibromoalkenes part 1: batch vs microflow conditions

International audienceThe generation and reactivity of two model vinyl carbenoids from gem-dibromoalkenes 1 CRlRs=CBr2 were studied in microflow systems. From substrate 1a (R = Ph, CF3), the lithium-bromine exchange could be simply performed within 30 ms at 20 °C with very good E-selectivity whereas the reaction was unselective under batch conditions, even at −78 °C. Moreover, the unstable carbenoid generated from 1b (R = Ph, H) could be trapped as the major product while only the Fritsch-Buttemberg-Wiechell rearrangement product was obtained in a flask under cryogenic conditions

Bromine-lithium exchange on gem-dibromoalkenes Part 1: batch vs microflow conditions

The generation and reactivity of two model vinyl carbenoids from gem-dibromoalkenes 1 were studied in microflow systems. From substrate 1a (R = Ph, CF3), the lithium-bromine exchange could be simply performed within 30 ms at 20 °C with very good E-selectivity whereas the reaction was unselective under batch conditions, even at −78 °C. Moreover, the unstable carbenoid generated from 1b (R = Ph, H) could be trapped as the major product while only the Fritsch-Buttemberg-Wiechell rearrangement product was obtained in a flask under cryogenic conditions