proteins

Researchers Find a Way to Unboil an Egg

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Consider this one of the fundamental truths as I was growing up and taking a number of courses in basic biology (and later, microbiology and chemistry): once you boil an egg, there is no way to unboil that egg. Proteins denature once subjected to heat, and do not re-fold back to their original shape/structure.

Turns out, based on most recent research, that may not necessarily be the case: According to findings published in the journal ChemBioChem,

University of California Irvine and Australian chemists have figured out how to unboil egg whites – an innovation that could dramatically reduce costs for cancer treatments, food production and other segments of the $160 billion global biotechnology industry.

…

To re-create a clear protein known as lysozyme once an egg has been boiled, he and his colleagues add a urea substance that chews away at the whites, liquefying the solid material. That’s half the process; at the molecular level, protein bits are still balled up into unusable masses. The scientists then employ a vortex fluid device, a high-powered machine designed by Professor Colin Raston’s laboratory at South Australia’s Flinders University. Shear stress within thin, microfluidic films is applied to those tiny pieces, forcing them back into untangled, proper form.

In a paper titled “Shear-Stress-Mediated Refolding of Proteins from Aggregates and Inclusion Bodies,” this is the abstract:

Recombinant protein overexpression of large proteins in bacteria often results in insoluble and misfolded proteins directed to inclusion bodies. We report the application of shear stress in micrometer-wide, thin fluid films to refold boiled hen egg white lysozyme, recombinant hen egg white lysozyme, and recombinant caveolin-1. Furthermore, the approach allowed refolding of a much larger protein, cAMP-dependent protein kinase A (PKA). The reported methods require only minutes, which is more than 100 times faster than conventional overnight dialysis. This rapid refolding technique could significantly shorten times, lower costs, and reduce waste streams associated with protein expression for a wide range of industrial and research applications.

Obviously, this is tremendous news that will seek other labs trying to replicate the study.

On Compatibility Genes: Can You Smell the Perfect Partner?

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The Guardian on whether humans have the ability to smell out suitable partners/mates, based on an upcoming book by Daniel M. Davis, The Compatibility Gene: How Our Bodies Fight Disease, Attract Others, and Define Our Selves:

The basis for this notion is the so-called smelly T-shirt experiment, first performed by a Swiss zoologist called Claus Wedekind in 1994. He analysed a particular bit of the DNA of a group of students, looking specifically at the major histocompatibility genes (MHC). The students were then split into 49 females and 44 males. The men were asked to wear plain cotton T-shirts for two nights while avoiding anything – alcohol, cologne etc – that might alter their natural odour. After two days the shirts were placed in cardboard boxes with holes in them, and the women were asked to rank the boxes by smell using three criteria: intensity, pleasantness and sexiness.

Wedekind’s results appeared to show that the women preferred the T-shirts worn by men with different compatibility genes from themselves, raising the possibility that we unconsciously select mates who would put our offspring at some genetic advantage. The experiment was controversial, but it did alter scientific thinking about compatibility genes. And while the mechanism behind this phenomenon is poorly understood, that hasn’t stopped dating agencies from employing MHC typing as a matchmaking tool.

Of course, there are labs out there taking advantage of this science:

One lab offering such testing to online agencies (you can’t smell potential partners over the internet; not yet), a Swiss company called GenePartner, claims: “With genetically compatible people we feel that rare sensation of perfect chemistry.”

But take all this with a big grain of salt, as the research is still preliminary and no one really understands how all this works:

It is not completely understood how all this works at the molecular level, but it is at this forefront that Davis toils. “My research is in developing microscopes that look with better resolution at immune cells and how they interact with other cells,” he says. This interaction is “reminiscent of the way neurons communicate” in the brain, raising the possibility that your compatibility genes are responsible for more than just fighting infection, and could even influence how your brain functions. I confess to Davis that I don’t really understand this part. “None of us do,” he says. “I just happened to write a book about it.”

But how does the smelling thing work – if it works? It has been shown that mice can, and do, detect compatibility genes by smell, and that stickleback fish also choose mates by their odour, but in humans, Davis admits, the jury is out. “How it works on the olfactory level is basically not understood at all,” he says.

I think the more interesting point from Davis’s research is this: since each human responds slightly differently to any particular disease, in the not-too-distant future vaccines and other medications may be tailored to match our compatibility genes.