Controlling them could lead to great progress

Dec 17, 2009 01:01 GMT  ·  By

One of the most important areas of scientific research in the world today is the one dealing with understanding how molecular machines function inside our bodies, regenerating it, and ensuring that we live long lives. How these components assemble is also something researchers are very interested in, so a lot of funds have been poured in this line of work. Enzymes are also a part of this class, and their full role in the body is barely beginning to be understood. Now, experts are looking for ways of refrigerating the active regions of enzymes, in a work that could have far-reaching implications.

After a lot of research in this direction, investigators finally believe they may have discovered a way of inserting what they refer to as a “cooling system” inside enzymes. Previous studies on the capabilities of these “machines” have already revealed their highly complex nature, and it would seem that they gain new abilities every time scientists look harder and deeper into what they do. But the one thing that unites the traits of all enzymes is the fact that they work best within a certain temperature range.

One thing that experts discovered was that all of the molecular machines in the body carried built-in, highly efficient, thermal management systems, Technology Review reports. In other words, it may be that evolution endowed these structures with the necessary means to regulate their own heat. Now, two researchers say they may have found the mechanism employed by enzymes to keep themselves within the optimum functioning temperature range. The two experts are Hans Briegel, from the University of Innsbruck in Austria, and Sandu Popescu, from the University of Bristol in the UK.

They explain that enzymes act like clamps, getting hold of biomolecules and keeping them in place. This reduces or boosts the chemical reactions in which these molecules are involved. When heat increases, so do vibrations in the clamps (which are called jaws). A higher vibration rate means that the enzymes become unable to keep the biomolecules in place, so they release them back into the original reactions. Cooling the jaws may increase the machines' performances and functions, but, until now, there has been no way of doing this.

Briegel and Popescu say that, when the enzymes overheat, changes in their shapes make the jaws “freeze.” When the entire ensemble is cooled again, the jaws pick up their usual routine. Every refrigerator, the team says, needs a power source, and it proposes that enzymes cooperate closely with the ATP group (the energy molecules of the body) for that. The thing about this approach and theory is that it can be fairly easily tested. Details of the idea appear in the journal arXiv, in a paper entitled “Intra-Molecular Refrigeration in Enzymes.”