Retrospectacle: A Neuroscience Blog

Water is good for a lot of things, from quenching your thirst to reducing the BO levels of your scuzzy roommate. But recent work from the University of Michigan, to be published next week in PNAS, shows that water is also an essential part of a type of cell enzyme called a ribozyme. Ribozymes accelerate chemical reactions inside cells, and are able to change their physical conformation between an ‘active’ and ‘inactive’ state.

Previous work in the lab of Dr. Nils Walter has shown that changes which occur anywhere on the ribozyme, even far away from the site of the reaction, change the rate at which the reaction occurs. This suggested that information about changes in distant parts of the ribozyme travels through a network to ribozyme’s core, where chemical reactions take place. The recent paper shows that water molecules trapped inside the ribozyme’s core are essential components of that network.

The network acts like a jostling crowd at a cocktail party, where hydrogen bonds—weak, electrostatic attractions between molecules or parts of molecules—take the place of handshakes. Water molecules trapped in ribozymes can form hydrogen bonds with other water molecules or with parts of the ribozyme molecule.
“The way we interpret the data is that in ribozymes, a chemical modification introduced at one place changes the local structure slightly,” Walter said. The building blocks making up the ribozyme wiggle into different positions and in the process must let go of some hydrogen bonds and form others, just as partygoers shift position and engage with other guests.
“As a consequence, their hydrogen bonding partners—some of which are water molecules—also rearrange. Then their hydrogen bonding partners also rearrange, creating a domino effect, where a local modification spreads throughout the molecule and modifies the structure elsewhere, even at quite a distance,” Walter said.

Go Blue!

Hat tip Bob Abu!

Comments

  1. #1 somnilista, FCD
    August 24, 2006

    I don’t see any mention in that press release of what technique they used. Is it NMR, crystallography, site-directed mutagenesis, or computer modelling?

  2. #2 darkman
    August 24, 2006

    wait, did they just do research to prove that water is important for life as we know it?

  3. #3 Comstock
    August 24, 2006

    You had me at the “all his base” comment at Aetiology, but then I pop over here and see “Go Blue” and my heart goes pitter-patter.

  4. #4 kemibe
    August 24, 2006

    I thought that most or all enzymes toggled back and forth between active and inactive states as a result of conformational changes, though not all of them involving H-bonding. But not only am I ignorant, I’m too lazy to look it up at this point in the day.

    How does water offset the stinkiness of a hygenically challenged roommate, by the way? I assume — and my condolences — that you speak from experience. Do you encouarge such specimens to drink lots of water to flush out toxins or do you soak them in it to quench the stench? (I had a weightlifter college roommate who was eating protein power for a while, and he stunk because the stuff made him fart like a Holstein. No amount of water would have helped, only a butt-plug. And his muscles got no larger, save, perhaps, for his smooth intestinal-wall muscle.)

  5. #5 Shelley Batts
    August 24, 2006

    I’m interested in the methods myself, the paper should be out soon and i’ll take a look then.

    Yes, I have had a very stink roommate, who probably only took showers 2x a month, or until I hinted at it (“Do you smell a rotting corpse too?”). I just encouraged contact with water, in any context for this guy. Lava soap too.

  6. #6 kemibe
    August 24, 2006

    Two showers a month? Christ in an autoclave. I know people who have come off three-month booze blackouts smelling better than that chap must have.

  7. #7 Terry
    August 28, 2006

    Great work, terrible headline. “Rehydrate — your RNA needs it”?

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