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Fast DNA Origami Opens Way For Nanoscale Machines

Posted by Soulskill on from the building-with-nano-cranes dept.

ananyo writes "DNA strands can be coaxed to fold up into shapes in a matter of minutes, reveals a study published in Science (abstract). The finding could radically speed up progress in the field of DNA origami. DNA origami involves using short DNA strands to hold a longer, folded strand in place at certain points, like sticky tape. Until now, assembling the shape has involved heating the DNA and allowing it to cool slowly for up to a week. But researchers at the Technical University of Munich in Germany have worked out that for most of the cooling period, nothing happens. But when a crucial temperature is reached, the whole structure forms suddenly. The researchers now aim to design nanostructures with optimal folding temperatures close to 37 C, the temperature at which mammalian cell cultures are grown, so that DNA machines could one day be used in biological settings."

21 comments

  1. programming by schneidafunk · · Score: 1

    From TFA: "So in 2004 and 2005 he spent months, he says, programming in his underpants, trying to work out a way to bend a 7,000-base-pair viral genome to his will. "

    Do these guys work from home or is he in his underpants at a lab?

    --
    Some people die at 25 and aren't buried until 75. -Benjamin Franklin
    1. Re:programming by Anonymous Coward · · Score: 0

      Mom's basement.

    2. Re:programming by Jeng · · Score: 1

      A tech support company I was working at had showers at one of their locations.

      Supposedly they closed off the showers after people were taking calls in towels.

      --
      Don't know something? Look it up. Still don't know? Then ask.
  2. WELCOME MY SON WELCOME TO THE MACHINE !! by Anonymous Coward · · Score: 0

    Where have you been ?? It's all right !! We know where you've been !! You've been in the pipline filling your time !!

    So Welcome !! To the machine !!

  3. Why not Protein instead? by m.shenhav · · Score: 2

    While I'm sure there are good reasons - could anybody with BioChemical expertise illuminate them?

    1. Re:Why not Protein instead? by TheCrazyMonkey · · Score: 2

      My guess is that custom proteins are harder to synthesize on demand. Generally if you want a custom protein you synthesize the DNA coding it, then insert it into a cell and have it produce the protein. Plus, DNA can be duplicated in vitro through conventional PCR where it's not really viable to transcribe proteins outside of a living cell.

    2. Re:Why not Protein instead? by Anonymous Coward · · Score: 2, Interesting

      My guess is that custom proteins are harder to synthesize on demand. Generally if you want a custom protein you synthesize the DNA coding it, then insert it into a cell and have it produce the protein. Plus, DNA can be duplicated in vitro through conventional PCR where it's not really viable to transcribe proteins outside of a living cell.

      While this is certainly all true, it is not the main reason. The main reason is design complexity. Single stranded DNA (ssDNA) has a really easy set of association rules; A pairs with T and G pairs with C. DNA origami is constructed of a viral DNA and many many DNA "staple" oligos, so the folding of DNA origami is actually done by one big dna molecule annealing to many shorter ones, which coax it to fold into cool shapes.

      If you compare this to proteins, which are strings of amino acids, which don't have easy rules about how they form their primary structure. Also designing arbitrary protein-protein interactions is much more complicated and currently an intractable problem.

    3. Re:Why not Protein instead? by Anonymous Coward · · Score: 0

      Not intractable, just really fucking hard:

      http://www.ncbi.nlm.nih.gov/pubmed/20460129
      http://www.ncbi.nlm.nih.gov/pubmed/21566186

    4. Re:Why not Protein instead? by Anonymous Coward · · Score: 0

      I'm familiar with the second work and I doubt even David Baker would say that /arbitrary/ protein-protein interactions are possible to design right now. That said the Baker lab has done some amazing stuff and in some cases it is doable and it's getting easier every day thanks to in part the Baker lab.

  4. 37 degrees -- shoulda guessed by Anonymous Coward · · Score: 0

    The critical temperature has to be close to the human/mammal body temperature. It's been known forever in statistical mechanics that DNA should unzip about the same temperature.

    1. Re:37 degrees -- shoulda guessed by NatasRevol · · Score: 1

      Well, mammals in general have a relatively wide body temperature. About 34-40C.

      And human body temperatures fluctuate across most of that range - exercise & sickness are easy points. What happens to DNA folding/protein building when body temp isn't at 37C?

      --
      There are two types of people in the world: Those who crave closure
    2. Re:37 degrees -- shoulda guessed by Anonymous Coward · · Score: 0

      If DNA unzipped at our body temperatures, we would be dead.

      Bzzzzzzzzz. Try again. The melting temperature for natural DNA is very high, and can be close to 100 deg C or more (depending on salt concentration).

    3. Re:37 degrees -- shoulda guessed by Anonymous Coward · · Score: 0

      Well, mammals in general have a relatively wide body temperature. About 34-40C.

      And human body temperatures fluctuate across most of that range - exercise & sickness are easy points. What happens to DNA folding/protein building when body temp isn't at 37C?

      The rate of folding either increases or decreases. Unless you get too far above the temperature at which the DNA folds. In that case no folding would occur and the DNA would remain in an unfolded disordered state. If it is already folded though, slight temperature fluctuations won't have any affect on the tertiary structure of the molecule.

    4. Re:37 degrees -- shoulda guessed by Anonymous Coward · · Score: 0

      That is extremities and outer-layer of body temperature. Deep within body temperature keeps constant 36.7 C. At which biochemical processes materialize.

    5. Re:37 degrees -- shoulda guessed by Anonymous Coward · · Score: 0

      Not exactly, the respiratory, circulitory, sweat, and other systems work very carefully to maintain the essential inner components at ~36.7 C, but "deep within" can fluctuate even in a healthy individual.

      Hypothermia happens when the internal typical body temperature drops around a degree or two and does not successfully re-adjust upward, and fever (a typical response to infections) results in a body-wide increase of a few degrees with a chance of damaging your own cells.

      So, while a 34 C body temperature is not healthy for a human, it is not outside of the range of survivable (as long as you get warmed up soon).

    6. Re:37 degrees -- shoulda guessed by NatasRevol · · Score: 1

      So you've never had a fever? Or ever heard of anyone ever having a fever? Ever?

      --
      There are two types of people in the world: Those who crave closure
  5. Duh! Chemistry 101 by Anonymous Coward · · Score: 0

    Certain chemical processes happen only at a certain temperature. That's why I got a D in chemistry. Didn't get it back then. Now I know. Metallurgy also involves chemical processes, but done at much higher temperature grades, some at 700 C, some at 1450 C...... Now, that's HOT!

  6. PAY ATTENTION by Anonymous Coward · · Score: 0
    We are starting to understand how matter organizes itself into life. Forget all the hoary old sci-fi cliches of space colonies and warp drives. Those will never happen, ever, under any currently understood system of physics and engineering.

    Life is about to get a whole lot more interesting and longer! Are you up for the challenge, or are you going to crawl back into your own belly and hide from reality?