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Nanotechnology: the Good, the Bad, the Hyperbole
pillageplunder writes "A very informative interview with Kristen Kulinowski who is an executive Director at the Federally funded Center for Biological and Environmental Nanotechnology at Rice University. A good well balanced read."
We've had a lot of rubbish about nanotech here in the UK, including the belief that a flesh-eating grey goo will take over the world. Honestly, our tabloid papers will report anything...
# cat
Damn, my RAM is full of llamas.
Shocking stuff, A robot with strands of DNA for legs!
While you're there you can also read about nano trees. The creators speculate that the technology could lead to "three-dimensionally interconnected computing structures analogous to the brain".
Smalley's Group (he and Curl discovered Buckyballs)
:)
Halas's Nanophotonics Group
CNST at Rice
Vicki Colvin's Intro to Nanoscience
Sorry, I couldn't find any sites about how nanoscience is going to kill us all
there are some remarkable examples of self-assembly in nature, besides the often given example of mitosis.
the key appears to be symmetry - identical units coming together in a way that is actually thermodynamically favorable.
consider the envelopes of viruses. very often these proteins envelopes take the form of platonic and archimedian solids, yet they are made from identical protein subunits (i.e. legos). within this protein, the dna or rna of the virus is housed.
but the neat thing is that you can add chemicals which will break the protein envelope apart into its subunits. if you then takes these pieces and leave them alone in solution for a while, the pieces will actually self-assemble into the original structure again (regardless of whether or not the nucleic acid of the virus is even present anymore, in most cases).
in this remarkable instance, the default position of nature is to self-assemble! and it is done in a way that does not involve a cell.
Sorry... I'm trained as a protein biochemist, and I can't help but comment on your post, which is basically correct, but may lead some people to think that viruses can self-replicate and self-assemble outside of the cell.
The reason the viral coat proteins self-assemble is that this is the most thermodynamically favorable state for these proteins in the aqueous environment in which the virus is replicating... i.e., the cell. The proteins have evolved such that their specific amino acid compositions make the assembled state most favorable. I suppose this is a valid analogy to what some nanotechnology research is tryin gto accomplish.
However, the proteins don't copy themselves and then self-assemble. The proteins are translated from the genetic material of the virus (DNA or RNA), and then the proteins self-assemble. The machinery that does this translation is most often provided by the host cell.
This is practically identical to how the cell itself replicates, although on a smaller scale. The genetic material is translated into proteins that can do the work required to make a new cell (copy the DNA, synthesize or import the lipids needed for the membrane, synthesize the proteins needed, and so on).
Sometimes, there are even special proteins called chaperones that help other proteins adopt their "correct" structure. I do not actually know of a case where this happens for viral proteins, but it wouldn't surprise me if one exists.
So... yes, once all the parts are produced, many viruses can self-assemble outside of a cell, as long as the conditions (pH, salt concentration, etc) are such that this is what is thermodynamically most favorable. But to get replication, you need the cell.