Menghini-4

Vincenzo Menghini (continued)


Fig. 1: E.F. Hoppe-Seyler, German doctor (1825-1895). He obtained haemoglobin in crystalline form and explained its function. (Credit: Today in Science History)

It was William Thomas Brande (1788–1866) who established in 1812 that the iron content in the dye of blood did not exceed that of the other substances of animal origin, therefore blood must contain a high percentage of "animal matter". Later on, in 1824, Sir Charles Scudamore (1779–1849) confirmed Brande’s observations and wrote that the dye of blood was an "animal principle" with a small iron content. Another forty years went by until E.F. Hoppe-Seyler discovered haemoglobin in 1864.


	Fig. 2: Max Perutz (1914-2002) and John F. Kendrew (1917-1977), winners of the Nobel Prize for Chemistry in 1962 for identifying the three-dimensional structure of haemoglobin and myoglobin. (Credit: Nobelprize.org)

Efforts to establish the structure of haemoglobin through x-ray crystalography took 30 years of hard work at the Cavendish Laboratory in Cambridge, under the chemist Max Perutz and his team. Perutz managed to obtain the structure of the metahaemoglobin of the horse in 1968. A few years earlier, in 1962, he won the Nobel Prize for Chemistry in recognition of his work in the field of structural biology. He shared the prize with Kendrew who worked on myoglobin – the equivalent of haemoglobin, which is found in the muscles. The haemoglobin of mammals is a protein made up of chains, two alpha and two beta. It is called a tetromer with a quaternary structure ₂₂. Each has a ring, known as an eme, containing a chemically coordinated ion Fe(II). Oxygen attaches itself irreversibly to the iron atoms, introducing a change in the structure of the haemoglobin. In practice, the haemoglobin acts as a molecular machine which transports the oxygen from the lungs to the sites where it is used, and from here it takes the carbon dioxide (as the ion
HCO₃^-), eliminating it through expiration. The oxygen does not attach itself to the four groups all at the same time; there is a mechanism which allows the haemoglobin to take the largest amount possible from the lungs and release it when and where it is most needed.

Fig. 3: Image of haemoglobin
(Credit: RCSB PDB-Protein Data Bank)

Fig. 4: Representation of myoglobin
(Credit: RCSB PDB-Protein Data Bank)

Fig. 5: View of Budrio
(Credit: Photo of Vittorio Bonaga)

He studied the action of various natural waters on urinary stones, not only looking at the type of stone but also at the relationship between the solvent power of the water and the amount in disolved salts. In this regard, in 1757 he published a pamphlet entitled On the disolving action of certain waters in bladder stones. Finally, he did some interesting research into the action of camphor on various types of insects and other animals.

Menghini received recognition from many authoritative sources. For example, the famous Macquer dictionary of chemistry (1778), referring to iron in the blood, states: "But the first person to carry out coherent research into this topic seems to have been Mr. Menghini, who demonstrated not only that blood contains a lot of iron, especially in the red part, but also that preparations containing this metal, once swallowed, pass mainly into the second tracts, cause various changes in the blood and can show up in analysis. The experiences of this doctor are most beautiful and quite satisfying". It is therefore right that the almost forgotten scientist Menghini be rediscovered by young people, together with the soft and hollow tones of the musical instruments of Budrio.

(Vincenzo Menghini - page 4 of 4)
< Back |

The Webweavers: Last modified Mon, 10 Oct 2006 11:20:35 GMT