Akiko Tadokoro

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Arginine-rich peptides, including octaarginine (R8), HIV-1 Tat, and branched-chain arginine-rich peptides, belong to one of the major classes of cell-permeable peptides which deliver various proteins and macromolecules to cells. The importance of the endocytic pathways has recently been demonstrated in the cellular uptake of these peptides. We have(More)
As the versatility and use of CPPs (cell-penetrating peptides) as intracellular delivery vectors have been widely accepted, the cellular uptake mechanisms that enable their efficient internalization have become the subject of much interest. Arginine-rich peptides, including HIV-1 Tatp (transactivator of transcription peptide), are regarded as a(More)
Intracellular delivery of bioactive molecules using arginine-rich peptides, including oligoarginine and HIV-1 Tat peptides, is a recently developed technology. Here, we report a dramatic change in the methods of internalization for these peptides brought about by the presence of pyrenebutyrate, a counteranion bearing an aromatic hydrophobic moiety. In the(More)
Escherichia coli spr (suppressor of prc) mutants and nlpI mutants show thermosensitive growth. The thermosensitivity of the spr mutants was suppressed by the nlpI mutations. Expression of the fusion genes encoding hexa-histidine-tagged NlpI (NlpI-His) and purification of the tagged NlpI showed that NlpI-His bound with Prc protease and IbpB chaperone.(More)
There is a growing number of reports showing the usefulness of cell-penetrating peptides (CPPs) including oligoarginines for intracellular delivery of macromolecules. Although the covalent attachment of the CPP segments to the cargo molecules is usually required to ensure effective delivery, conventional methods of conjugation need several manipulation(More)
Arginine-rich peptide-mediated protein delivery into living cells is a novel technology for controlling cell functions with therapeutic potential. In this report, a novel approach for the intracellular delivery of histidine-tagged proteins was introduced where a Ni(II) chelate of octaarginine peptide bearing nitrilotriacetic acid [R8-NTA-Ni(II)] was used as(More)
Successful intracellular delivery of various bioactive molecules has been reported using cell-permeating peptides (CPPs) as delivery vectors. To determine the effects of CPPs on the cellular uptake of immunoglobulin Fab fragment, conjugates of a radio-iodinated Fab fragment with CPPs (CPP-(125)I-Fab) derived from HIV-1 TAT, HIV-1 REV, and Antennapedia (ANP)(More)
Arginine-rich cell-penetrating peptides (CPPs), including human immunodeficiency virus type 1 (HIV-1) Tat (48-60) and oligoarginines, have been applied as carriers for delivery of cargo molecules, because of their capacity to internalize into cells and penetrate biological membranes. Despite the fact that they have been extensively studied, the factors(More)
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