Lactoferricin-Derived L5a Cell-Penetrating Peptide for Delivery of DNA into Cells


Cell-penetrating peptides (CPPs) are small peptides which help intracellular delivery of functional macromolecules, including DNAs, RNAs, and proteins, across the cell membrane and into the cytosol, and even into the nucleus in some cases. Delivery of macromolecules can facilitate transfection, aid in gene therapy and transgenesis, and alter gene expression. L5a (RRWQW), originally derived from bovine lactoferricin, is one kind of CPPs which can promote cellular uptake of plasmid DNA and enters cells via direct membrane translocation. The peptide complexes noncovalently with DNA over a short incubation period. DNA plasmid and L5a complex stability is confirmed by a decrease in mobility in a gel retardation assay, and successful transfection is proven by the detection of a reporter gene in cells using fluorescent microscopy. Here, we describe methods to study noncovalent interactions between L5a and plasmid DNA, and the delivery of L5a/DNA complexes into cells. L5a is the one of the smallest CPPs discovered to date, providing a small delivery vehicle for macromolecules in mammalian cells. A small vehicle which can enter the nucleus is ideal for efficient gene uptake, transfer, and therapy. It is simple to complex with DNA plasmids, and its nature allows mammalian cells to be easily transfected.


Biological Sciences


This work was supported by the Center for Biomedical Research at Missouri University of Science and Technology, and the Ministry of Science and Technology, Taiwan.

Keywords and Phrases

Cell-penetrating peptide; Electrophoretic mobility shift assay; Fluorescent microscopy; Gel retardation; Gene therapy; Intracellular delivery; N/P ratio; Protein transduction domain; Transgenesis

International Standard Serial Number (ISSN)

1064-3745; 1940-6029

Document Type

Article - Journal

Document Version


File Type





© 2020 Springer, All rights reserved.

Publication Date

01 Jan 2021

PubMed ID