Hallym University; Fusion of HIV Tat PTD at both termini improves protein uptake

2004 FEB 18 – (NewsRx.com & NewsRx.net) — Fusion of the HIV Tat PTD to both termini of therapeutic proteins may improve the efficiency of cell entry.

“Poor membrane permeability of proteins is a major limitation of protein therapy,” scientists in South Korea explained.

“In a previous study, we showed that the minimal sequence required for efficient transduction of Tat-GFP is the basic domain from 49-57 of HIV-1 Tat called the protein transduction domain (PTD),” noted J. Ryu and coauthors at Hallym University, who “generated HIV-1 Tat PTD GFP fusion proteins in which HIV-1 Tat PTD is fused with the N- and/or C-termini of GFP.”

“The various GFP fusion proteins were purified from Escherichia coli and characterized for their ability to enter mammalian cells using Western blot analysis, confocal microscopy and flow cytometry,” according to the report. “The GFP fusion protein with Tat PTD at its C-terminus was taken up as efficiently as the GFP fusion protein with Tat PTD at its N-terminus. However, the same protein with PTDs at its both termini was taken up even more efficiently.”

“All the GFP fusion proteins were present in both the nucleus and cytosol of the transduced cells,” test results showed. “Uptake was lower at 4 degrees C than at 37 degrees C.”

“The availability of the expression vectors developed in this study may help to devise novel strategies in the rational development of protein-based drugs,” the researchers concluded.

Ryu and colleagues published their study in Molecules and Cells (Enhanced uptake of a heterologous protein with an HIV-1 tat protein transduction domains (PTD) at both termini. Mol Cells, 2003;16(3):385-391).

For additional information, contact J. Park, Hallym University, Department of Genetic Engineering, Division of Life Science, Chunchon 200702, South Korea.

The publisher’s contact information for the journal Molecules and Cells is: Springer-Verlag Singapore Pte Ltd., #04-01 Cencon I, 1 Tannery Rd., Singapore 347719, Singapore.

The information in this article comes under the major subject areas of AIDS & HIV, Biotechnology, Pharmaceutical & Drug Development, Proteomics and Virology.

This article was prepared by Biotech Week editors from staff and other reports. Copyright 2004, Biotech Week via NewsRx.com & NewsRx.net.