Dendrimers with sugar interiors could be used as enzyme mimics
A new type of three-dimensional polymer containing sugar units inside the macromolecule itself has been synthesised by researchers at the Max-Planck-Institute for Polymer Research, Germany. The interior of this new molecule is lipid-like despite containing sugar units which could make it useful as a mimic for enzyme active sites.
These three-dimensional polymers are called dendrimers. As with other polymers, dendrimers are made up of repeat units but here the repeat units branch out from a central core. Research into glycodendrimers - dendrimers containing sugar - has focused on molecules where the sugars are attached only to the surface. However, in the current work by Klaus M?llen, sugar units are in the repeat unit. This means that the sugar units are built into the inside of the macromolecule. Based on previous work, the repeat units of this glycodendrimer are densely packed. This arrangement of units means the macromolecule keeps its shape in solution providing a regular, structured interior.
M?llen was interested in how the interior sugar units affected the micro-environment within the dendrimer. To probe the dendrimer and determine how hydrophobic it was, the team used a common fluorescent probe. Surprisingly, the lipid-like hydrophobic nature of the inside of the glycodendrimer was almost unchanged when compared with a dendrimer containing only surface sugar units. In many ways, the interior of this glycodendrimer is similar to the hydrophobic pockets found in natural enzymes, say the researchers.
In this work the authors ’demonstrate the ease of mixing and matching the hydrophilic and hydrophobic components’, explained George Newkome, vice president, research & dean, graduate school, University of Akron, US. These glycodendrimers also have the potential to act as host molecules.
J Sakamoto and Klaus Müllen, Org. Lett., 2004, 6, 4277