Bionanoscience

Collagen is the glue that holds our bodies together. It can be found in our skin, bones, muscles, cartilage, ligaments, hair, nails - in short, in almost every tissue in our body. In some places, for example in the skin, collagen proteins form networks that are very elastic. But why these networks are so elastic has so far been unclear. Researchers from Delft University of Technology, AMOLF and Wageningen University & Research have now discovered that the number of 'intersections' plays an important role. Between three and four connections per intersection is ideal. In fact, more connections makes the collagen networks less elastic. The new insights can be used, among other things, to repair damaged or aged tissue, such as cartilage or skin, and to grow new skin tissue for burn victims.

DNA in a cell can normally be compared to spaghetti on one’s plate: a large tangle of strands. To be able to divide DNA neatly between the two daughter cells during cell division, the cell organises this tangle into tightly packed chromosomes. A protein complex called condensin has been known to play a key role in this process, but biologists had no idea exactly how this worked. Until February 2018, when scientists from the Kavli Institute at Delft University of Technology, together with colleagues from EMBL Heidelberg, showed in real time how a condensin protein extrudes a loop in the DNA. Now, follow-up research by the same research groups shows that simple bundling up such loops is by no means the only way condensin packs up DNA. The researchers discovered an entirely new loop structure, which they call the 'Z loop'. They publish this new phenomenon in Nature on 4 March, where they show, for the first time, how condensins mutually interact to fold DNA into a zigzag structure.