Thursday, January 28, 2010

Pyroglue: Underwater, Heat Resistant Molecular Glue Based on Proteins of New Archaeal Fimbriae Revealed by German Molecular Biologists, Protein Subunit Named Fbr or Fimbrin




Pyroglue. It works under water.  It can take high heat and retain its adhesion. Nanobiotechnology makes this molecular glue stick.  In this case nanotechnology is used to mimic nature’s superglues. It has medical, household, construction and technological uses

University of Regensburg Institute for Microbiology Professor Reinhard Wirth (Regensburg, DE) and Christine Thoma  (Landshut, DE) concocted an adhesive material composed of  protein from fimbriae and from archaea. Preparation of an adhesive material includes the step of isolating and/or purifying at least one protein obtained from "archaea or archaeal fimbrin", according to the inventors in U.S. Patent Application 20100022758,

No functional studies for archaeal fimbriae have been published on the subject according to Wirth and Thoma. The research data however show that M. thermoautotrophicus is able to adhere onto surfaces via its fimbriae. Since the present invention identifies for the first time the protein constituting such a surface organelle it is proposed to use it as a new kind of "pyroglue". In the following the new archaeal fimbrial subunit protein will be called Fbr or fimbrin.

Compounds of nature have since decades attracted the interest of researchers. Researchers have learned and still learn from biology how to apply attainments from nature. In particular, nanobiotechnology is an emerging area of scientific and technological opportunity.

Nanobiotechnology applies compounds and structures of nature if, e.g. synthetically produced products cannot comply with extreme requirements, e.g. heat, moisture etc. One example for synthetically produced products are glues which are mainly produced by chemical synthesis. These glues, when applied to biological systems show disadvantages insofar as they leach, may be toxic and/or are incompatible with the biological system etc.

The problem underlying the present invention is the development of a glue which is heat stable and/or which can also be applied in wet and moist environments. Presently used glues are often epoxy based, cement based or based on synthetic polymers. Both the epoxy compounds and the synthetic polymers may leach and constitute a risk to the environment. Their application often requires mechanical working or kneading of the glue or sealing agent, in order to remove the water present on the surfaces. There is a need for new glues, better adapted for use in warm and/or moist environments or for underwater use and more environmentally friendly than the present products.

The applications for such a protein glue are seen in the field of nanobiotechnology. Proteins acting as molecular cement to connect part A to part B do not have the disadvantage of chemicals which might interfere with the biological functions of one of the parts. Quantum dots e.g. have to be functionalized by a shell of polyacrylic acid to allow conjugation to macromolecules and ligands.  

The adhesive property of the archaeal fimbrins, in particular the fimbrin obtainable form M. thermoautotrophicus, are particularly useful in medical as well as in technological settings.

The adhesive fimbrin may be used in medical applications, for example as a component in wound dressings and bandages, in particular in such applications where the biodegradable properties of the protein are needed. It is also envisaged that the adhesive property of archaeal fimbrins be employed in the coating of (medical) bands and strings. Since the archaeal fimbrins as documented by the researchers have an ability to attach to surfaces, and to form an attachment between surfaces, they may be used as a tissue adhesive.

 The adhesive capability of fimbrin (Fbr protein) may, accordingly, be used as an adhesive for plasters, adhesives, bandages, patches and dressings etc. The protein may also be useful in orthopaedics as a glue to keep or hold joint replacements together. It is also envisaged to use the adhesive properties of the fimbrins as surface coating of medical and/or surgical devices and tools, e.g. stents, chirurgical nails, or transplants. The use of the adhesive fimbrins derived from archaeal fimbrin in dental medicine is also envisaged, for example in the anchorage/attachment of artificial tooth parts or crowns. Furthermore, the use of the adhesive fimbrins may be used in dental restoration or for dental implants. .

Surface organelles of prokaryotes may be differentiated into those used for motility (named flagella) and those used for adhesion (in most cases named fimbriae). In the case of eubacteria some fimbriae have been defined (at least for some species like the Enterobacteria Escherichia coli and Salmonella typhimurium) to a very high resolution, which is true for molecular and functional aspects
FIG. 1 Comparison of bacterial flagella (S. typhimurium), archaeal flagella (P. furiosus) and archaeal fimbriae (M. thermoautotrophicus), in particular, with respect to their diameter.



FIG. 2 TEM picture of a cell of Methanothermobacter thermoautotrophicus Ag5 grown in suspension in a serum bottle. Few cell appendages named fimbriae are visible on the cell.



FIG. 3 TEM picture of a carbon coated gold grid incubated in a serum bottle used for growing Methanothermobacter thermoautotrophicus Ag5. Cells grow on these gold grids to a much higher density than in suspension (FIG. 3A); multiple surface appendages named fimbriae are visible on the cells (FIG. 3B) at the top of the story.




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