Related Experiment Video
Updated: Feb 2, 2026

Fluorescent Leakage Assay to Investigate Membrane Destabilization by Cell-Penetrating Peptide
Published on: December 19, 2020
Dipicolylamine/Metal Complexes that Promote Direct Cell-Membrane Penetration of Octaarginine
Yoshimasa Kawaguchi1, Shoko Ise1, Yusuke Azuma1
1Institute for Chemical Research , Kyoto University , Uji, Kyoto 611-0011 , Japan.
Abstract:
Marked promotion of membrane permeation of a cell-penetrating peptide, octaarginine (R8), was attained by attachment to a single 2,2'-dipicolylamine moiety (DPA-R8) that forms 1:1 complexes with metal ions. Studies using giant unilamellar vesicles demonstrated that DPA targets phospholipids and enhances R8 binding to the membranes in the presence of metal ions. While DPA/Zn(II) complex has been most frequently employed for chelate formation with phosphates, Ni(II) had the most prominent effect on the membrane binding and penetration of DPA-R8. Facile cytosolic distribution of DPA-R8 was also attained in a few minutes in the presence of Ni(II). Analysis of the cellular uptake methods of DPA-R8/Ni(II) suggested the involvement of direct permeation through cell membrane without the use of endocytosis. The applicability of this system to the intracellular delivery of bioactive compounds was exemplified using a peptidomimetic farnesyltransferase inhibitor, FTI277.
Related Concept Videos
Anaphase Promoting Complex
The Eukaryotic Promoter Region
Metallic Solids
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
Bonding in Metals
Alkali Metals
Table 1: Properties of the alkali metals

