Blog search results for Tag: protein

Agrifood

Thinking of popping to your nearest specialist store for some sesame oil, turmeric, or soy? Some things haven't changed in 3,700 years, it turns out...

At least, that's what a growing new field of research, palaeoproteomics, suggests. Human mouths are full of bacteria, which continually petrify and form dental calculus — which can entrap and preserve tiny food particles. These remnants can be accessed and analysed thousands of years later, providing remarkable insight into the dietary habits of our ancestors.

Philip Stockhammer, an archaeologist at the Ludwig Maximilian University of Munich (LMU), has worked with Christina Warinner, a molecular archaeologist at Harvard University and the Max Planck Institute for the Science of Human History, and a team of researchers to apply this new method to the eastern Mediterranean, including the Bronze Age site of Megiddo and the Early Iron Age site of Tel Erani.

“Our high-resolution study of ancient proteins and plant residues from human dental calculus is the first of its kind to study the cuisines of the ancient Near East,” said Warinner, explaining its significance. “Our research demonstrates the great potential of these methods to detect foods that otherwise leave few archaeological traces. Dental calculus is such a valuable source of information about the lives of ancient peoples.”

SCIblog - 1 March 2021 - A trip to the Bronze Age dentist - image of woman's smile with perfect teeth

High-resolution analyses of ancient dental calculus have given us a whole new perspective on the diets of Bronze Age people.

The research team took samples from a range of individuals and analysed which food proteins and plant residues were preserved in their teeth. “This enables us to find traces of what a person ate,” said Stockhammer. “Anyone who does not practice good dental hygiene will still be telling us archaeologists what they have been eating thousands of years from now!”

Of course, it's not quite as simple as looking at the teeth of those who didn't thoroughly clean them nearly four millennia ago and hoping the proteins survived. “Interestingly, we find that allergy-associated proteins appear to be the most stable in human calculus”, remarked Ashley Scott, LMU biochemist and lead author. That might be because of the known thermostability of many allergens. For instance, the researchers were able to detect wheat via wheat gluten proteins, which they independently confirmed with a different method using a type of plant microfossil known as phytoliths.

This substance has previously been used to identify millet and date palm in the same area during the Bronze and Iron Ages but phytoliths are not plentiful or even present in many foods, which is why this research is so exciting — palaeoproteomics means foods that have left few other traces, such as sesame, can now be identified.

SCIblog - 1 March 2021 - A trip to the Bronze Age dentist - image of a pile of bananas

Research suggests that the humble banana was eaten throughout the Mediterranean far earlier than first thought.

The method has allowed the team to identify that people at these sites ate, among other things, sesame, turmeric, soy, and bananas far earlier than anyone had realised. “Exotic spices, fruits and oils from Asia had thus reached the Mediterranean several centuries, in some cases even millennia, earlier than had been previously thought,” explained Stockhammer.

The finds mean that we have direct evidence for a flourishing long-distance trade in fruits, spices, and oils, from East and South Asia to the Levant via Mesopotamia or Egypt as early as the second millennium BCE.

More than that, the analyses "provide crucial information on the spread of the banana around the world. No archaeological or written evidence had previously suggested such an early spread into the Mediterranean region,” according to Stockhammer (although the sudden appearance of bananas in West Africa a few centuries later has previously led archaeologists to believe that such a trade might have existed, this is the first evidence).

The team acknowledged that other explanations are possible, including that the individuals concerned had travelled to East or South Asia at some point but there is evidence for other trade in food and spices in the Eastern Mediterranean — for instance, we know Pharaoh Ramses II was buried with peppercorns from India in 1213 BCE.

But it certainly seems like some foods might have been popular in the Mediterranean for much longer than we realised, which might be an interesting thought to accompany you next time you add some spices or bananas to your shopping basket.

Health & Wellbeing

It’s quite likely that most people who end up in the vicinity of a scorpion will more than likely beat a hasty retreat, not least because they can impart a potentially life threatening dose of venom should one get stung.

But scientists are now finding that the venom from these creatures, along with snakes and spiders, could be beneficial in treating heart attacks. Scorpion venom in particular contains a peptide that has been found to have a positive impact on the cardiovascular system of rats with high blood pressure. Reporting their findings in Journal of Proteome Research, scientists from Brazil, Canada and Denmark say that they now have a better understanding of the processes involved.

 An emperor scorpian

Emperor Scorpion 

Scorpion venom is a complex mixture of molecules including neurotoxins, vasodilators and antimicrobial compounds, among many others. Individual venom compounds, if isolated and administered at the proper dose, could have surprising health benefits, the researchers say.

One promising compound is the tripeptide KPP (Lys-Pro-Pro), which the researchers say is part of a larger scorpion toxin. KPP was shown to cause blood vessels to dilate and blood pressure to decline in hypertensive rats.

 A blood vessel on organic tissue

A blood vessel on organic tissue

To understand how KPP worked, the researchers treated cardiac muscle cells from mice, in a Petri dish, with KPP and measured the levels of proteins expressed by the cells at different times using mass spectrometry. They found that KPP regulated proteins associated with cell death, energy production, muscle contraction and protein turnover. In addition the scorpion peptide triggered the phosphorylation of a mouse protein called AKT, which activated another protein involved in production of nitric oxide, a vasodilator.

Treatment with KPP led to dephosphorylation of a protein called phospholamban, which led to reduced contraction of cardiac muscle cells. Both AKT and phospholamban are already known to protect cardiac tissue from injuries caused by lack of oxygen. The researchers said that these results indicate that KPP should be further studied as a drug lead for heart attacks and other cardiovascular problems.

 

Conceptual image for cardiovascular problems .