Slashdot Mirror


Supercomputer Sets Protein-Folding Record

Nicros writes with this snippet from Nature News: "A specially designed supercomputer named Anton has simulated changes in a protein's three-dimensional structure over a period of a millisecond — a time-scale more than a hundred-fold greater than the previous record. ... The simulations revealed how the proteins changed as they folded, unfolded and folded again. 'The agreement with experimental data is amazing,' says Chandra Verma, a computational structural biologist at the Bioinformatics Institute of the Agency for Science, Technology and Research in Singapore. Simulating the basic pancreatic trypsin inhibitor over the course of a millisecond took Anton about 100 days — roughly as long as computers spent toiling over previous simulations that only spanned 10 microseconds."

21 of 63 comments (clear)

  1. Even though it was published in Nature News... by blind+biker · · Score: 4, Interesting

    ..it's a rather poor article. It talks in very basic terms about proteins and their folding, talks a bit more about the scientist who founded the institute behind the computer, and says fuck-all about the construction of the computer itself.

    Bah. For a publishing house of Nature Publishing Group's (intellectual and economic) muscle, one should expect more.

    --
    "The agriculture ministry is not in charge of Gundam" - Japanese ministry official.
    1. Re:Even though it was published in Nature News... by ikkonoishi · · Score: 4, Informative

      Here this should give you more information.

      http://en.wikipedia.org/wiki/Anton_(computer)

      I think the article was alright though. It told what was going on, and why it could be important. It wasn't written for a computer nerd demographic so the exact specs weren't really relevant.

    2. Re:Even though it was published in Nature News... by Anonymous Coward · · Score: 2, Funny

      It wasn't written for a computer nerd demographic so the exact specs weren't really relevant.

      You are writing for a nerd demographic though so you should have said "It wasn't written for a computer nerd demographic so it missed out all the most important information."

    3. Re:Even though it was published in Nature News... by anguirus.x · · Score: 5, Informative

      The best way is to just compare them to the actual structure which is known from x-ray crystallography and NMR studies. They could do isotopic replacement studies to get ideas about which hydrogrens or nitrogens or carbons were kinetically involved in the folding process and see whether the same atoms were important in the simulation. If they're the same it could just be a coincidence, or it could be an indication that the folding itself is accurate on the computer, not just the final structure. This is truly amazing, but we've still got a long ways to go. MOAR COMPUTERS PRZ!

    4. Re:Even though it was published in Nature News... by serviscope_minor · · Score: 2, Insightful

      ..it's a rather poor article. It talks in very basic terms

      That's because it's in nature news, which does rather high-level, short coverage of a wide range of topics for a very broad scientific audience. It's meant to be a "hey look this is cool" article, that you can read up more about if you are interested and have the right kind of background. Perhaps you were thinking it was a ahort or regular article?

      --
      SJW n. One who posts facts.
    5. Re:Even though it was published in Nature News... by imsabbel · · Score: 2, Interesting

      Nature and Science are not for hard science.

      If you just get articles from citation search its not obvious why, but if you ever see a print issue it becomes obvious:

      They cover a _huge_ range of fields. You can have articles about egyptian mummies, rainforrest status in south america, neutron scattering and virus chrystallography within 20 pages or so.

      So people have to write the arcticles in a way that at least readers from most of the fields involved can understand it and see why it is important. Otherwise, it would better to publish it in a publication of a narrower scope.

      --
      HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
    6. Re:Even though it was published in Nature News... by the+gnat · · Score: 2, Insightful

      The best way is to just compare them to the actual structure which is known from x-ray crystallography and NMR studies.

      And so far, this is the only way that most researchers are willing to trust. There is a very good reason why these folding studies tend to focus on a small group of well-defined model systems, because the folded native structure is already very well understood, and it provides an essential constraint on the interpretation of results. Using ab initio physics calculations like this for truly blind structure prediction would be a complete waste of time, and the entire field figured this out decades ago.

    7. Re:Even though it was published in Nature News... by the+gnat · · Score: 4, Informative

      Nature and Science are not for hard science.

      The actual research articles are hard science - this was just a news story for a general audience. The official publication of the results in Science magazine appears to be a pretty serious piece of work, and it's significant enough that the editors allowed them to make it reasonably long instead of a (severely compressed) three- or four-page summary article like most of what they publish. There are lots of valid criticisms of those two journals, starting with their length requirements, but they're not Scientific American, and publishing in one of these is practically a prerequisite for getting a faculty position in biosciences at a major research university.

    8. Re:Even though it was published in Nature News... by ElektronSpinRezonans · · Score: 3, Informative

      This was not an ab initio, calculation. It's all atom MD, which itself is an approximation. People have done ab initio calculations on 10-15 residue peptides, but that's about all you can do with current computational power.

      I believe the article is published in Science not because of its computer utilization (i.e. using a bad-ass super computer), but because of its biological relevance. They managed to characterize not only the peptides conformations, but also their mutant's behavior in silico.

    9. Re:Even though it was published in Nature News... by the+gnat · · Score: 3, Insightful

      This was not an ab initio, calculation. It's all atom MD, which itself is an approximation

      Sorry, I meant "ab initio MD", although I realize that to a chemist or physicist this is a total oxymoron. (My background is molecular biology and bioinformatics, where we try not to think about quantum chemistry.) I should have written "physically-based", if you prefer, as opposed to the knowledge-based approaches that have been most successful for de novo structure prediction. (I think most MD "force fields" are ultimately based on genuinely ab initio QM calculations.)

  2. Processing power by cjfs · · Score: 2, Funny

    The performance of a 512-node Anton machine is over 17,000 nanoseconds of simulated time per day for a protein-water system consisting of 23,558 atoms

    So... how many libraries of congress per second??

  3. applause! by StripedCow · · Score: 2, Insightful

    This research is extremely important for finding new drugs, and therefore I applaud the originators of the project, especially D.E. Shaw who apparently put also a lot of funding into it. I wish more (rich) people put their money into such immensely useful projects. It is not just a noble thing to do, it is also smart, since we all could one day benefit from this kind of research.

    --
    If Pandora's box is destined to be opened, *I* want to be the one to open it.
  4. not really by pigwiggle · · Score: 3, Insightful

    This has been the promise of computer simulation - "in silico" drug design - for decades. It hasn't panned out. And I say this as someone who makes a living doing exactly what these folks have done. High throughput bench work is far more efficient, time and money wise, than computer simulation. Hard to say when or if that will change.

    --
    46 & 2
    1. Re:not really by StripedCow · · Score: 2, Interesting

      According to the article, it now takes 100 days to do one simulation. If we had 100 times the processing power (maybe a little more accounting for overhead), then we could do it in one day. I'd say that would be possible today with sufficient financial support, or at least it could be a reality within a decade. In short, it still sounds promising to me..

      --
      If Pandora's box is destined to be opened, *I* want to be the one to open it.
    2. Re:not really by Anonymous Coward · · Score: 2, Interesting

      100 days is for a 'hero run', the bread and butter runs last 1-4 days apiece and account for more like 20-100 microseconds of simulated time. One of the big innovations of this machine is that those runs would otherwise take months on other machines.

    3. Re:not really by WrongMonkey · · Score: 2, Insightful

      I totally agree with you. I think it should always be pointed out the inherent limitation of these models. D.E. Shaw Research, Folding@home and many others use a force-field model that is fundamentally Newtonian. It doesn't take into account any quantum dynamics, it can't model the formation or dissociation of chemical bonds and most of the simulation parameters aren't much better than a wild guess. There used to be an implicit assumption in the computational chemistry community that all of those little errors would cancel out for large molecules, such as proteins. But, personally, I don't think that assumption has held up very well to experimental scrutiny.

  5. Re:The folly of folding@home by the+gnat · · Score: 4, Informative

    That's a little unfair to Folding@Home. Shaw has a lot of resources to pour into this project - he's lured faculty members away from universities to work for him instead and has the equivalent of several large labs worth of advanced researchers. He also has an immensely larger budget than most non-profit labs, and he's self-employed so he doesn't have to answer to granting agencies or tenure committees. I think what he's doing is great but he's really one of the only people who could have pulled this off. It's difficult to know what approach will work best in advance, and both Shaw and Vijay Pande have been very innovative in approaching the problem from completely different angles.

    By the way, this approach has been tried before with less stellar results - I'm thinking of the MD-GRAPE project in Japan. You're also assuming that every problem is equally well suited towards custom ASICs, but actually, molecular dynamics is far easier to do this with than many other methods. For instance, Rosetta (Rosetta@Home and Fold.It) is doing structure prediction, not folding, using a mostly statistics-based energy function and Monte Carlo sampling, and this isn't something you can trivially offload to a specialized chip. In that case, distributed computing is by far the most efficient solution.

  6. Re:Hundred-fold greater? by Samantha+Wright · · Score: 4, Informative

    No, Anton simulated one millisecond over the course of a hundred days. The previous recordholder took roughly the same time to do a hundredth of the work. (This was probably the RIKEN MDGRAPE-3, but again, documentation is le sparse.)

    --
    Bio questions? Ask me to start a Q&A journal. Computer analogies available for most topics!
  7. Re:The folly of folding@home by blackraven14250 · · Score: 2, Insightful

    Good thing F@H runs on the GPU, which is many times faster than the CPU at these operations.

    Also, don't forget what it takes to build supercomputer capable of doing this, and that resources put into building supercomputers are then not available for the consumer market. Distributing this stuff allows for a compromise between absolute best performance and letting people have powerful computers at home.

  8. Re:The folly of folding@home by SoftwareArtist · · Score: 2, Insightful

    Actually, Folding@Home can also simulate these time scales by means of Markov state models. The trajectory is pieced together out of data collected from many short simulations, whereas the Anton trajectory is generated from a single MD run, but in practice that distinction is usually irrelevant. Protein dynamics are stochastic, so for any time scale longer than about 1 ns, both approaches given equally "realistic" or "valid" trajectories.

    That's not to criticize Anton. It's an amazing piece of hardware and they're doing amazing work with it. But of the two approaches, Markov state models are probably going to prove more valuable in the end. They make more efficient use of whatever computational resources you have available, they give more insight into the structure of the folding pathway, and they can be run on commodity hardware that many more people have access to. David Shaw has even admitted they'll eventually have to start using them. By the third generation of Anton, he expects to have hit limits on how far they can parallelize a single MD run, so Markov state models will be the only way they can keep adding processing power.

    --
    "I'm too busy to research this and form an educated opinion, but I do have time to tell everyone my uninformed opinion."
  9. Re:Ah, the human body by HiThere · · Score: 4, Interesting

    It is complex, but you are ignoring the relative isolation between levels that exists in the human, and rat, body.

    Protein folding may be complex, but most of it is irrelevant detail. What's usually important is the final shape that one ends up with, e.g. But when wants to modify that process, then the details of that process become important. This is roughly equivalent to...at the level that I work, I pay no attention to how the compiler is going to optimize my code. If I wanted to modify that I'd need to pay attention to things at a much finer level of detail.

    It *is* true that people tend to oversimplify things they aren't dealing with directly. But to make it a fair statement it needs to be made fully *that* general. (This doesn't make you original assertion false, but observationally it *is* false. I've never known a knowledgeable geek that oversimplified the biochemistry of life in the way that you painted. I'm sure they exist, but they aren't, as you implied, common. If they are common among your friends, well, then you have some uncommon friends.)

    --

    I think we've pushed this "anyone can grow up to be president" thing too far.