Cigarettes are printed on the "smoking is harmful to health." Indeed, smoking is an important carcinogenic factor. However, at least one person in the world is benefiting from smoking. At present, the international research team led by the University of Rice has found the reasons.
A young woman and her father all had the same mutation, the woman had anemia, and her father did not. Why is that? John Olson, a biochemist at the University of Rice, is working with researchers in Germany and France to try to reveal the secrets.
This is the father and daughter mutation is the gene encoding hemoglobin, hemoglobin is responsible for absorbing and transporting oxygen to the body cells. So far, more than 1,000 mutations have been found in human hemoglobin. Most of the human body has no effect, if the disease occurs, it is called hemoglobin disease, and often to find its city or hospital to name. In this case, the family lived in Mannheim, Germany, but the father was born in the Turkish city of Kirklareli.
Kirklareli mutations did not affect the iron content of the father's blood, but it seemed to be the underlying cause of chronic anemia among young women. Researchers through further investigation found that the absorption of carbon monoxide from cigarette smoke can treat this rare genetic disease. They published the findings in Journal of Biological Chemistry.
Mutations occur in the human hemoglobin alpha subunit (H58L), leading to its rapid self-oxidation, which makes the protein split, losing heme and precipitating. As a result, the protein loses its ability to carry oxygen, and eventually the red blood cells themselves are deformed and destroyed. It is worth noting that this mutation makes the protein's affinity for carbon monoxide 80,000 times higher than oxygen. Carbon monoxide in cigarettes is selectively absorbed by mutated hemoglobin to prevent its oxidation and deformation. This also explains why the father has no signs of anemia.
"He may never be an athlete because his blood can not carry too much oxygen, but smoking prevents him from anemia," Olson said. "There is also an added benefit that people of this trait are more tolerant of carbon monoxide poisoning. Olson said he did not know how the doctor treated the young woman
"She should not smoke," he said. "But she can take an antioxidant, such as a lot of vitamin C, which will help prevent the mutated hemoglobin from being oxidized. Her anemia is not too serious, and she does not need to worry too much about secondhand smoke, which may be positive for her Effect."
At that time, her doctor in the exclusion of blood loss, gastritis or congenital defects and other common causes, her illness was once helpless. So he turned to Emmanuel Bissé, a researcher at the Institute of Clinical Chemistry at the University of Freiburg in Germany. Bissé found a mutation after sequencing the female's DNA.
Later, Bissé invited Olson and his team to help determine why histidine-to-leucine changes led to her daughter rather than father's anemia. It is interesting to note that Ivan Birukou, a graduate student at Olson Laboratories, has produced the same mutations on hemoglobin to study how the protein binds quickly and selectively to oxygen.
Olson recalls: "Emmanuel wrote to me and said, 'I know you've been doing mutants of hemoglobin, you might have had an alpha chain of H58L mutations. Do you think this phenotype makes sense?'"
"I said, 'We can do a good research because we have generated mutated hemoglobin in the recombination system.' Actually we have a matching crystal structure that has not yet been published but has been placed in the protein database PDB. We use this mutation to understand the role of distal histidine in the alpha subunit. "
This histidine forms a strong hydrogen bond with oxygen. In their 2010 study, they found that the use of leucine instead of histidine resulted in a significant decrease in the affinity with oxygen and an increase in binding to carbon monoxide. Olson and Birukou realize that histidine plays a key role in binding oxygen or carbon monoxide. "When Emmanuel wrote to me about his discovery, I already knew what had happened," Olson said.
"When you touch it, sugar hydrogen and oxygen form hydrogen bonds with the polysaccharides on your fingers," Olson said. "This viscosity helps to catch oxygen, but leucine is more like an oil, such as butane or ethane, so that oxygen can not be well adhered to hemoglobin."
Olson Lab's postdoctoral researcher Andres Benitez Cardenas made a key experiment. He introduced carbon monoxide into the Kirklareli hemoglobin mutant alpha subunit. The combined carbon monoxide slows the oxidation of the protein and prevents the loss and precipitation of heme. "Andres did a smoking experiment to prove why his father's hemoglobin was invariant and lead to anemia," Olson said. He said the effects of such mutations were rare, but not unique.
"There is another 'smoky of health' mutation," he said, that was the discovery of Zurich in the late 1970s and early 1980s. Researchers at the time sought the help of the Nobel Prize winner Max Perutz, who won the Nobel Prize for his groundbreaking work on hemoglobin structures.
"Emmanuel knows that we have studied the mutations of these histidine to leucine in myoglobin and hemoglobin, so we have contacted us," he said. "This type of cooperation illustrates how science and medicine should promote each other."
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