Tree-like molecules proteins

Lipids form membranes inside and around the cell. Carbohydrates form complex tree-like molecules that become attached to the surface of proteins and cellular membranes. In both cases, the three-dimensional molecular structure is not unique, but the molecular assemblies are highly flexible. Thus, analyzing the molecular structure involves the inspection of a process in time. Molecular dynamics is the only available computer-based method for doing so. Compared with protein structures there are relatively few results on lipids and carbohydrates. The book does not detail this topic. 

Dendritic architectures have attracted the interest of many scientists recently. The aesthetically pleasing tree-like moleeules combine advanced synthesis and unique properties with the prospects of supramolecular technologies. The guest-host properties of these well-defined macromolecules are of great interest, because they resemble the interactions of small molecules with biomacromolecules like proteins, and they are able to close the gap between the traditional supramolecular interactions of smaller molecules and the interactions in larger (phase-separated) macromolecular systems. In recent years a large number of interesting results have been reported, in which supramolecular interactions and dendritic architectures are combined. 

The acetylcholinesterase enzyme has a fascinating tree-like structure (Fig. 11.45). The trunk of the tree is a collagen molecule which is anchored to the cell membrane. There are three branches (disulfide bridges) leading off from the trunk, each of which hold the acetylcholinesterase enzyme above the surface of the membrane. The enzyme itself is made up of four protein subunits, each of which has an active site. Therefore, each enzyme tree has twelve active sites. 

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