Nobel Prize for lapses in memory

03/01/2013

Sometimes scientists make discoveries not on purpose, but it can be said, quite by accident. Thus, a molecular biologist Christian de Duve, Rene discovered cellular organelles lysosomes because before that left a cooked product for a few days in the fridge and forgot about it. For this "forgetfulness" scientist won the Nobel Prize.


Everyone knows that the Nobel Prize is given for outstanding discoveries, but few know exactly what preceded them. No doubt, sometimes lead to the discovery of targeted and precisely targeted action, but it also happens that the scientist finds is not what he had planned (and it turns out to be far more valuable than the intended result). Or the discovery is the result of completely random actions. And then it seems logical that the Nobel Prize is awarded "for sloppiness", "for failing to keep clean" (remember the story of Alexander Fleming) or "for forgetfulness." It was about the last will and our story, the more that this story took place during the Christmas holidays. And its main character is a wonderful Belgian biologist Christian de Duve, Rene.

This outstanding scientist, who was then working in the laboratory at the medical school of the Catholic University of Louvain, in fact initially worked very different things that are unlikely to bring him to a great discovery — he studied the mechanism of action of the hormone insulin. However, in this area the results of his work is now known only to specialists. But now, any student or student who enjoys biology knows that such important cellular organelles like lysosomes and peroxisomes, had been opened by Christian De Dyuvom.

In fact, since that time, as was discovered living cell, scientists could not understand one, in general, is quite a simple thing: what is the mechanism of intracellular digestion? The observations showed that the cell is fully capable to "swallow" fairly large organic particles and digest them, but no one knew how. Of course, biologists have suspected that inside it has all the necessary enzymes, but where they are and how they work, could not say no researcher.

In addition, there was another problem of a systemic nature — after all, if these enzymes break down organic matter, they must be dangerous for the cell itself — because it consists of the same organic molecules. So, just like that in the cytoplasm, they can not be — otherwise the latter will be quickly digested by them. But where the cell secretes these hazardous substances? And why did they start working only when next to them there is food? These questions do not have clear answers, although there was speculation, of course, a lot.

But back to the work of De Duvall — a scientist who is this specific problem is not particularly interested in, at some point realized that to study the biochemical properties of the cells to divide them into separate components by centrifugation. For sufficiently rapid rotation of the cellular contents into fractions, which turned out to various cell components by weight. Thus the elementary unit of all living things can be "disassembled for parts."

Fascinated by the new method (which has developed his friend and colleague Albert Claude), de Duve and his staff immediately began to centrifuge the cells in the liver of rats and will soon have a number of different factions. They were as follows: a core containing chromosomes; mitochondria, which play the role of "power plants" of the cell, microsomes (later called ribosomes) and the supernatant — the liquid part of the cell. However, the distinction is not particularly happy with the researchers, and they soon figured out how to divide each fraction at sub-factions. This has given biologists the opportunity to explore almost every organelle properties individually.

So, almost immediately after the first successful experiments de Duve and his colleagues found that the activity of the enzyme acid phosphatase present in the mitochondrial fraction, on the fifth day after fractionation was much higher than the first day. This is very interested researchers — it seemed like something mysterious because the enzyme is not an active component of the mitochondria. However, it was already known that acid phosphatase, catalyzes the breakdown of organic molecules with the detachment of phosphate groups involved in the cellular digestion. But what is she doing in this group? And why its activity increased with the passage of time?

Reflecting on this, Christian de Duve before the Christmas holidays in 1949, prepared several mitochondrial fractions and put them in the freezer, hoping to study the issue after the holidays. When he appeared again after the holidays, in the laboratory, it is not immediately thought of the preparations, and they stayed there a few more days. Finally, thinking about fractions and pulling them out of the fridge, the scientist saw that they made preparations for some reason … all of a sudden were analyzed (ie themselves digested).

De Duve carefully examined the remains of the factions and realized what happened next — formed crystals of frozen water that damaged the mysterious containers that held these same enzymes. Now it was necessary to find out what it was for storage. De Dyuvu managed to separate the mitochondrial fraction in the sub-factions, and there he found a strange bubbles surrounded by a membrane. Inside, they showed up and acidic phosphatase and other digestive enzymes. So de Duve discovered one of the most important cellular organelles — the lysosome, which is due to intracellular digestion.

Later, the scientist and his colleagues found, why is contained in the lysosome enzymes do not damage the shell itself storage. It turns out that all of them work only under acidic conditions, but in repose within the lysosome Wednesday, strictly neutral.

When there is a connection to this organelle vesicle carrying food that comprises a molecular "pump", is pumped into the digestive vacuole formed hydrogen ions. Environment becomes acidic, and enzymes "are included." By the way, this was the explanation for the fact that the activity of acid phosphatase increased within five days after the fractionation. The fact that the "pump" is often started just after mechanical contact with any lysosomal vesicle. Thus, centrifugation simply "included" enzymes.

Later, in the mid-50s of the last century, De Duve and his colleagues have discovered another cell organelle — peroxisomes, which contained a large number of enzymes that catalyze oxidation-reduction reactions (it was named so because one of the functions of this organelle is the decomposition harmful to the cells of hydrogen peroxide). And for all that, in 1974, De Dyuvu together with Albert Claude and George E. Palade was awarded the Nobel Prize in Physiology or Medicine.

Needless to say, the presentation of this prestigious award in the present case correctly — in fact, the opening of the de Duval allowed to unravel the many mysteries of cell physiology. However, it should be noted that the scientist had to thank her for her forgetfulness without which the award would be hardly possible …

Anton Evseev

Like this post? Please share to your friends: