Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New function of a bacterial photoresponsive protein: Resisting adhesion of mammalian cells

01.03.2012
Non-fouling materials that resist cell adhesion are very important in fundamental research on cell–biomaterial interactions and for practical applications.

Thus, they have been extensively investigated during the last decade. Natural biomacromolecules such as bovine serum albumin (BSA) have conventionally been used to block cell adhesion. Zhao and Ding (Fudan University, Shanghai, China) recently reported that the purple membrane (PM) containing a natural photoresponsive protein, bacteriorhodopsin (BR), can serve as a new basic substance that resists adhesion of mammalian cells.


Purple membrane containing the retinal protein bacteriorhodopsin (BR) was coated onto glass. The coated film resisted adhesion of mammalian cells, while the purple membrane retained its biological activity. This is the first report of a non-fouling substrate with photoelectric and photochromic responses. This material consists of natural biomacromolecules. Credit: © Science China Press

BR is a retinal-containing bacterial protein that is present in the PM region of the bacterial membrane. The PM is the simplest biological system for energy conversion. Excitation of BR with a photon causes a photocycle, resulting in uptake of a proton from the cytoplasmic side of the PM and release of another proton to the extracellular side. BR and similar retinal proteins have attracted much attention as potential optical materials for applications in 2-D or 3-D storage, holographic storage, optical filtering, light switching, neural networks, super-fast photo detection, motion detection, and artificial retinas, etc., and also as model proteins in fundamental research.

Nevertheless, the PM had not been recognized as a non-fouling material for preventing cell adhesion. Adhesion is the first cellular event that occurs when a cell comes into contact with a material surface, and it influences subsequent cellular events such as proliferation and differentiation. Non-fouling surfaces are useful for studies on cell–material interactions for generating patterned surfaces of contrasting adhesion, and they are also useful for controlling cellular and bacterial adhesion in medical applications and/or in complex bio-related environments. A number of non-fouling substances have been reported, including polyethylene glycol (PEG) or oligoethylene glycol (OEG), PEG hydrogels, poly(N-isopropylacrylamide) or its copolymers, and the globular protein, BSA. This study affords a new choice of non-fouling substance, because the PM containing the membrane protein BR was shown to resist cell adhesion.

Our results reveal that the natural PM has significant resistance to cell adhesion. This non-fouling property is very beneficial for potential applications of BR materials, for instance, as biosensors in complex environments. The finding also affords an excellent model substance that resists cell adhesion, which could be useful in surface modification of biomaterials for regenerative medicine. The photoresponsive property of BR distinguishes it from all of the currently known anti-fouling substances.

It is also worth noting that many other retinal proteins such as rhodopsin, halorhodopsin, xanthorhodopsin, and archaerhodopsin, are light-driven ion pumps. Therefore, a direct extension of this work would be to examine possible non-fouling properties of other retinal proteins. Further studies are required examine the resistance to adhesion of other types of mammalian and non-mammalian cells. Hence, while the mechanism by which the PM prevents non-specific protein absorption remains an open question, this report paves the way for further investigations and new applications of BR and possibly other light-sensitive proteins.

Reference
Zhao YC, Ding JD. Purple membrane resists cell adhesion. Chin. Sci. Bull., 2012, 57(2-3), 234-237

Ding Jian-dong | EurekAlert!
Further information:
http://www.fudan.edu.cn

More articles from Life Sciences:

nachricht Scientists spin artificial silk from whey protein
24.01.2017 | Deutsches Elektronen-Synchrotron DESY

nachricht Choreographing the microRNA-target dance
24.01.2017 | UT Southwestern Medical Center

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Scientists spin artificial silk from whey protein

X-ray study throws light on key process for production

A Swedish-German team of researchers has cleared up a key process for the artificial production of silk. With the help of the intense X-rays from DESY's...

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Breaking the optical bandwidth record of stable pulsed lasers

24.01.2017 | Physics and Astronomy

Choreographing the microRNA-target dance

24.01.2017 | Life Sciences

Spanish scientists create a 3-D bioprinter to print human skin

24.01.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>