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 Exciting Plant Vacuoles
14.06.2019 | Julius-Maximilians-Universität Würzburg

nachricht A microscopic topographic map of cellular function
13.06.2019 | University of Missouri-Columbia

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: MPSD team discovers light-induced ferroelectricity in strontium titanate

Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.

Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...

Im Focus: Determining the Earth’s gravity field more accurately than ever before

Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.

The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...

Im Focus: Tube anemone has the largest animal mitochondrial genome ever sequenced

Discovery by Brazilian and US researchers could change the classification of two species, which appear more akin to jellyfish than was thought.

The tube anemone Isarachnanthus nocturnus is only 15 cm long but has the largest mitochondrial genome of any animal sequenced to date, with 80,923 base pairs....

Im Focus: Tiny light box opens new doors into the nanoworld

Researchers at Chalmers University of Technology, Sweden, have discovered a completely new way of capturing, amplifying and linking light to matter at the nanolevel. Using a tiny box, built from stacked atomically thin material, they have succeeded in creating a type of feedback loop in which light and matter become one. The discovery, which was recently published in Nature Nanotechnology, opens up new possibilities in the world of nanophotonics.

Photonics is concerned with various means of using light. Fibre-optic communication is an example of photonics, as is the technology behind photodetectors and...

Im Focus: Cost-effective and individualized advanced electronic packaging in small batches now available

Fraunhofer IZM is joining the EUROPRACTICE IC Service platform. Together, the partners are making fan-out wafer level packaging (FOWLP) for electronic devices available and affordable even in small batches – and thus of interest to research institutes, universities, and SMEs. Costs can be significantly reduced by up to ten customers implementing individual fan-out wafer level packaging for their ICs or other components on a multi-project wafer. The target group includes any organization that does not produce in large quantities, but requires prototypes.

Research always means trying things out and daring to do new things. Research institutes, universities, and SMEs do not produce in large batches, but rather...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

Concert of magnetic moments

14.06.2019 | Information Technology

Materials informatics reveals new class of super-hard alloys

14.06.2019 | Materials Sciences

New imaging modality targets cholesterol in arterial plaque

14.06.2019 | Medical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>