Two Ounces of Prevention

Two recent papers to come out of the Weizmann Institute have possible medical applications — one in preventing pregnancy, the other in preventing the deadly effects of nerve gas.

The first might give pause to those among us who are “believers” in antioxidants. It seems that those “nasty” molecules they eliminate — reactive oxygen species — have a positive role to play, at least when it comes to fertility. In the study, mopping up reactive oxygen species with antioxidants in mouse ovaries blocked ovulation. So while women who are trying to get pregnant might consider knocking off the acai juice and vitamin E, the findings imply that various antioxidants might eventually be adapted for non-hormonal birth control.

The second is on the development of an enzyme that breaks down certain nerve agents before they can wreck havoc on muscles and nerves. Interestingly enough, our bodies make a version of this enzyme, known by the acronym PON1. This enzyme is a sort of jack of all trades: Among its primary talents, it can break down fatty deposits on artery walls. Prof. Dan Tawfik has been intrigued by the evolution of this enzyme: How could the leisurely course of evolution produce an enzyme for breaking down a chemical that was only invented around 50-60 years ago?

One of the insights of his research team: The same evolutionary process that produced this enzyme could be employed in the laboratory to create a new enzyme variant that is much more efficient and focused on one of its tasks. By applying mutation and selection to generations of PON1 in a test tube, he and his research team were able to create a new enzyme that protects against certain nerve gases, even at relatively high exposures.

Comments

  1. #1 WcT
    January 26, 2011

    Prof. Dan Tawfik has been intrigued by the evolution of this enzyme: How could the leisurely course of evolution produce an enzyme for breaking down a chemical that was only invented around 50-60 years ago?

    Is this really as surprising as phrased? Surely it’s more surprising that 50-60 years ago we developed a novel chemical that manages to closely interact with people in a way as to rapidly kill them, and it’s similar enough to natural chemicals that we already have built-in ways to affect those molecules.
    On re-read that sounds surprisingly incoherant but I feel the thrust of my comment is understandable.

  2. #2 Weizmann Science Writer
    January 26, 2011

    It’s a little more complicated than that, as the enzymes interact specifically with the organophosphates, and not with other, naturally-occurring toxins. Tawfik’s idea is that enzymes like PON1 have a robust function and, in addition, one or more highly mutable ones that can evolve into separate functions if natural selection pushes them in that direction — sort of a jump start on evolution. See some of his previous research: http://wis-wander.weizmann.ac.il/site/en/weizman.asp?pi=422&doc_id=4156&interID=4151&sq=4151

  3. #3 Birger Johansson
    January 26, 2011

    Fascinating. But the ID believers might say this proves God has a time machine (aka prophecy). And when we find the real explanations, the IDers will totally ignore it.

    It would be nice if we could find enzymes preventing death from other classes of nerve gas than the organophosphates. Anything that forces the weapons manufactureres to choose more expensive solutions will deter local arms races. Today’s nerve gases are much too cheap to manufacture (example: Iraq).

  4. #4 altın çilek
    January 30, 2011

    s this really as surprising as phrased? Surely it’s more surprising that 50-60 years ago we developed a novel chemical that manages to closely interact with people in a way as to rapidly kill them, and it’s similar enough to natural chemicals that we already have built-in ways to affect those molecules.

  5. #5 seslichatsohbetler
    February 9, 2011

    Tesekkurler.Fascinating. But the ID believers might say this proves God has a time machine (aka prophecy). And when we find the real explanations, the IDers will totally ignore it.