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 Molecular Force Sensors
20.09.2017 | Max-Planck-Institut für Biochemie

nachricht Foster tadpoles trigger parental instinct in poison frogs
20.09.2017 | Veterinärmedizinische Universität Wien

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

Im Focus: Silencing bacteria

HZI researchers pave the way for new agents that render hospital pathogens mute

Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Molecular Force Sensors

20.09.2017 | Life Sciences

Producing electricity during flight

20.09.2017 | Power and Electrical Engineering

Tiny lasers from a gallery of whispers

20.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>