ScienceDaily (July 14, 2010) — Scientists are reporting discovery of a way to help proteins such as the new generation of protein-based drugs -- sometimes heralded as tomorrow's potential "miracle cures" -- get past the biochemical "Entrance Forbidden" barrier that keeps them from entering cells and doing their work.

The new technique, described in the monthly journal, ACS Chemical Biology, represents a new use for an engineered form of green fluorescent protein, the topic of the 2008 Nobel Prize in Chemistry that is one of the most important research tools in biosciences.

In the report, David Liu and his colleagues describe the difficulty of delivering proteins from the outside of mammalian cells into their interiors. For that reason, nearly all of the blockbuster drugs that are proteins must do their work on the exterior of cells, activating receptors that send signals to the interior. This constraint greatly limits the scope of protein-based drugs. Liu's solution: Attaching proteins to molecules of "supercharged" green fluorescent protein, which they mutated to give it a very high positive charge. When the hybrid proteins bump into the surface of a cell, they get pulled inside by negatively charged molecules called proteoglycans.

Liu and his team tested the hybrid proteins on five types of cells, and found that they were extremely good at carrying their protein cargo inside. In fact, the supercharged protein was up to 100 times better at getting proteins into cells compared to other approaches. The delivered proteins were able to go to their target locations in the cell, such as the nucleus or cytoplasm, and perform their jobs. "To our knowledge, this is the first report of functional delivery of an enzyme into retinal cells in vivo," the researchers state.

Recommend this story on Facebook, Twitter,
and Google +1:

Other bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by American Chemical Society, via EurekAlert!, a service of AAAS.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

1. Cronican et al. Potent Delivery of Functional Proteins into Mammalian Cells in Vitro and in Vivo Using a Supercharged Protein. ACS Chemical Biology, 2010; 100624142152055 DOI: 10.1021/cb1001153

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Related Stories

Chemists Design New Way to Fluorescently Label Proteins (June 1, 2010) — Since the 1990s, a green fluorescent protein known simply as GFP has revolutionized cell biology. Originally found in a Pacific Northwest jellyfish, GFP allows scientists to visualize proteins inside ...  > read more

Expression Of Infrared Fluorescence Engineered In Mammals (May 16, 2009) — Researchers have shown that bacterial proteins called phytochromes can be engineered into infrared-fluorescent proteins. Because the wavelength of IFPs is able to penetrate tissue, these proteins are ...  > read more

Green Fluorescent Protein Pioneers Share 2008 Nobel Prize In Chemistry (Oct. 8, 2008) — The Royal Swedish Academy of Sciences has awarded the Nobel Prize in Chemistry for 2008 jointly to Osamu Shimomura, of the Marine Biological Laboratory and Boston University Medical School, Martin ...  > read more

Biomedical Research Profits From Exploration Of Deep Sea (Nov. 27, 2008) — Exploration of the ocean depths can benefit humankind. This is the story of a voyage of discovery, starting with marine animals that glow, the identification of the molecules responsible and their ...  > read more

Search ScienceDaily