urine biophysics

October 17, 2012 at 1:50 pm | | literature

The Shape of the Urine Stream — From Biophysics to Diagnostics.

Definitely an Ig Nobel contender.

lion hunter?

October 11, 2012 at 1:16 pm | | nerd

What are the chances that the only person cc’d on this email would be “LHunter”?

Also, anyone wanna go get coffee? I know a shortcut through the woods. Here, put this antler hat on.

2012 nobel in chemistry: Kobilka and Lefkowitz

October 10, 2012 at 9:52 am | | news, nobel

Well, I predicted G-protein coupled receptors (GPCRs) and Brian Kobilka, but not Robert Lefkowitz. Congrats to both!

GPCRs are cell-surface receptors that translate signal from an extracellular ligand to a G-protein, a molecular “switch” turned on and off by GTP. (The discovery of the G-protein was awarded the 1994 Nobel in Medicine). GPCRs are very important in a variety of signaling in the human body, and most modern drugs target GPCRs.

Kobilka and Lefkowitz first had inklings of the structure of GPCRs in the 80s, when they began isolating and purifying the β2-adrenergic receptor (βAR). They eventually realized that the protein had seven transmembrane helices; to their surprise, that hinted at a very similar structure to rhodopsin—the component in the eye responsible for detecting light—another GPCR. This discovery implied that all the receptors that couple to G-proteins might have a conserved structure! Over the last few decades, Kobilka, Lefkowitz, and others have produced a bunch of structures for GPCRs, which should aid in future drug design.

I think it’s fascinating is that Kobilka was a postdoc with Lefkowitz many years ago. I wonder how often it happens that both the professor and a student/postdoc share a Nobel? Of course, Kobilka has performed enough work during his independent career to earn a Nobel, but I still think it’s cool that he won the award with his former professor. I’m not sure why Stevens or Palczewski were not also included in the prize, but it seems that the committee (given only three available slots, of course) stuck to the early discoveries that lead to the GPCR structures.

And I must discuss the concern from many corners that this is not “chemistry.” Why did it not win the medicine prize, instead? Well, I don’t know. It certainly could have won the prize in the medicine category, because of GPCR’s huge role in medicine! But the Nobel Committee seems to often place protein structures into the chemistry category [Update: see this great history]. I think that is reasonable: the task of isolating, purifying, crystallizing, and determining the structure of a protein is basically biochemistry, not medicine. And many of the individuals in the lab performing the tasks are probably chemists and biochemists. Maybe the lab isn’t located in a chemistry building, but neither is the lab that I work in, and I am certainly a chemist performing chemistry. (Well, right now I’m blogging.) I continue to think that these type of discoveries being labeled “chemistry” is great for the field of chemistry. Maybe I feel this way because I don’t perform “traditional” chemistry synthesizing small organic molecules. My research has spanned polymer physics, spectroscopy, optics, and cell biology. But I have applied my skills and knowledge of a physical chemist to all those sciences. As I said in my interview with Slate.com (where I did not predict GPCRs):

The line between chemistry and other fields (especially biology) is often blurred, and that’s a wonderful thing; but this fact sometimes results in a chemistry Nobel Prize being awarded for a decidedly biological discovery (like the 2009 prize for the structure of the ribosome). This may be exacerbated by the fact that the physiology or medicine prize tends to go to things directly related to health, and the chemistry prize often is used to cover the more basic biological science feats. Personally, I think it is a testament to the central position the field of chemistry holds in the Venn diagram of science.

Biology is the next frontier for the physical sciences! There is so much to learn about how biomolecule, cells, and organisms work. Let’s embrace biology’s commingling with chemistry with all our hearts!

You can read more about GPCRs here:






Other bloggy commentary here:








October 3, 2012 at 2:39 pm | | news, nobel, science and the public, science community

Paul and I were interviewed for a Slate.com article about Nobel Prize predictions. More details back at my original post on the 2012 Prize.

the precautionary principle is flawed

October 1, 2012 at 10:28 am | | news, science and the public

I’ve always warned against the Precautionary Principle, mainly because it has a fatal flaw: no one applies the same principle to the alternatives. The Precautionary Principle assumes a product (or medicine or technology) is harmful until it is proven to be safe, instead of the other way around. This sounds nice, but the problem is that it doesn’t take into account the dangers of the alternative products (or medicines or technologies). That is, at least how most consumers apply the principle.

I warned against this when the BPA kerfuffle emerged. Many people started to get concerned about bisphenol A, which is a monomer for polycarbonate used in many plastic bottles. Some BPA can leach from the plastic into food or liquids, and there has been some evidence that it may mimic hormones in the human body and may have negative health effects especially in children. So everyone started banning BPA bottles and switching to other materials. The main alternative is “BPA-free” plastics. When this happened, I asked, “But what are those plastics made of??”

Basically, everyone switched over from a known product (polycarbonate) that might have some deleterious effects, to a proprietary polymer (Eastman’s Tritan) that we knew nothing about. And everyone felt safe.

But what if Tritan is a thousand times more dangerous? What if the glass bottles that some people switched to leaches lead (although I doubt many parents are giving their kids crystal to drink out of)? What if those steel water bottles put chromium into your water? (The aluminum ones like Sigg are coated with a plastic, anyway.) It doesn’t really make tons of sense to throw away your old water bottles to buy brand new ones that have a new, proprietary plastic that can leach new, unknown chemicals into your water.

C&E News has a story about Eastman’s Tritan and it’s possible health dangers. We should all throw away our new water bottles and start drinking out of another unknown material so another company can make billions off of our fears. Or just start drinking directly from the faucet.

The only correct application of the Precautionary Principle is to have someone measure the safety of all the materials used to make water bottles and baby sippy cups and weigh the dangers against each other. Maybe Eastman should pay for that. ;)

(That said, I must admit that I drink out of glass, a coffee mug made in China, and a steel water bottle. Who knows what I have in my body.)

Thanks for the tip, Chemjobber.

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