Researchers have recently created the smallest, tightest knot ever seen, made up of only 54 atoms. The knot is in the form of a trefoil, which is the simplest type of nontrivial knot, with three interlaced crossings and no loose ends. This newly formed “metallaknot” is made of gold and assembles itself, as described in a new paper published on Jan. 2 in the journal Nature Communications. Study co-author Richard Puddephatt, a chemist at the University of Western Ontario, explained that the scientists stumbled upon this double-record-breaking knot unintentionally. Originally, they were attempting to link carbon structures to gold acetylides, a type of chemical compound. During this process, one of the reactions produced a golden chain that tied itself into a tangle resembling a three-leaf clover.Related: RNA ties itself in knots, then unties itself in mesmerizing videoThe process involved in the creation of this knot is quite complex, and the researchers are uncertain about how it occurs, according to Puddephatt.As well as being incredibly small, the knot is also the tightest ever tied, according to the study. Knot tightness is measured by its backbone-to-crossing ratio (BCR), with a smaller value representing a tighter knot. The previous record holder for the tightest knot had a BCR of 24, but this new trefoil just edges it out with a BCR of 23.”Molecular knots, whose synthesis presents many challenges, can play important roles in protein structure and function as well as in useful molecular materials, whose properties depend on the size of the knotted structure,” the researchers wrote in the study.For instance, knot structures are essential for binding together DNA, RNA and proteins that the human body relies on. Trefoil knots, specifically, are fundamental in knot theory as they are the only tangles with just three crossings and can be built upon when combined with other knots. Investigating the mysteries of knots could also have practical applications in real life, from developing more effective plastics to creating new types of chemotherapies.
