Building the invisible masterpieces of a molecular machine

(Nanowerk News) There is no doubt about the impact of the nanotechnology to modify our understanding of matter, that has extended its scope to applications hardly imaginable just a few decades ago. With the ability to manipulate small molecules or even atoms at will, chemists are nowadays able to design and develop novel materials whose dimension are one millionth of a millimeter, building these materials using components of just one nanometer.
In the last few years the scientist, by combining the technological advances together with the chemical tools, can not only prepare nanomaterials in an efficient manner, but also study their properties and finally develop new applications. Not surprisingly last Nobel Prize in Chemistry was awarded to first impellers of the smallest and most fascinating gadgets developed in the last few years: the ‘molecular machines’.
Researchers around the world are working in this field to make programmable molecules in a reasonable time, which should carry out functions assigned by their creators. Researchers at CiQUS (Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares) have developed small cyclic compounds as basic components of new molecular materials, but recently they gave one step further in the preparation of new molecular machine components, reporting their new achievements in the peer-reviewed chemical journals JACS (Journal of the American Chemical Society) and Nanoscale. In these articles, they describe the work carried out by the young researchers Lionel Ozores and Alberto Fuertes.
In the first case, they prepare a self-assembling capsule or molecular container that can entrap small molecules in the internal cavity which presents a complementary shape, and that are later released under appropriate conditions (JACS, "Self-Assembling Molecular Capsules Based on α,γ-Cyclic Peptides").
self-assembling cyclic peptide
Capsule based on a β-sheet self-assembling cyclic peptide with the ability to recognize and release several guests. (© ACS)
As Lionel Ozores says, "we are talking about a reversible process that can be controlled by the media conditions; these systems might have application in the development of new drug delivery systems, in strategies for molecular cleaning in which the toxic molecules are encapsulated to reduce its toxicity".
The second approach provides a quite unique molecular shape with important potential applications (Nanoscale, "Self-assembling Venturi-like peptide nanotubes").
They describe the first molecular tube with an internal constrain. At the macroscopic level they are known as Venturi tubes and are used to calculate the speed of a fluid. They have numerous applications in different fields, such as aspiration tubes used in dental clinics, water pumps used in carburetors or aquariums, etc.
Self-assembling peptide nanotube
Self-assembling peptide nanotubes that have an internal filter area and whose length and internal diameters, at the entrance and in the constricted area. (© RSC)
However, at the microscopic level they might have applications as models of the membrane channel proteins that are the responsible of transporting ions across the biological membranes, due to their structural similarity: "these proteins play a very important role in our sensorial system, and their malfunction give rise to different disordered and diseases", says Alberto Fuertes, first author in this work and very optimistic regarding his findings: "we hope these molecular components might be a new step towards the development of molecular machines that will improve our quality of life", he says. Both articles have been carried out under the supervision of USC Professors and CiQUS researchers Juan R. Granja and Manuel Amorín.
Source: CiQUS