Fast DNA Origami Opens Way For Nanoscale Machines

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."

Comments

programming

[schneidafunk]

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?

Re:programming

[Jeng]

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.

Why not Protein instead?

[m.shenhav]

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

Re:Why not Protein instead?

[TheCrazyMonkey]

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.

Re:Why not Protein instead?

[Anonymous Coward]

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.

Re:37 degrees -- shoulda guessed

[NatasRevol]

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?

Re:37 degrees -- shoulda guessed

[NatasRevol]

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