In 1885–1901 Albrecht Kossel (1853–1927) isolated and described purines. In subsequent studies he and his students discovered pyrimidine nitrogenous bases – components of nucleic acids.
Phosphoric acid and an unknown carbohydrate were also found in the products of nuclein hydrolysis. Phoebus Levene (1869–1940) was able to obtain deoxyribose – the same carbohydrate, and he also identified the components of DNA.
We have come a long way in the study of DNA… Now it was necessary to find out on what principle this molecule was built.
Erwin Chargaff (1905–2002) – it is with his name, more precisely with his research, that the secret of DNA, which we have to uncover, is connected.
Between 1949 and 1951, biochemist Erwin Chargaff and his group made a major discovery. They determined the quantitative ratio of purines and pyrimidines in DNA. In the future, the spatial structure of the molecule will be built, where the principle of complementarity of nitrogenous bases will be observed, and the founder of this is Erwin Chargaff. DNA contains the code of heredity, and in order to protect it, it was necessary for just such a structure of purines and pyrimidines.
So, all the components of DNA were found, the main provisions were formulated, it remained only to collect all the accumulated material to create the spatial structure of DNA. However, one important component was still missing… It was a DNA X-ray. X-ray diffraction studies are related to the names of Rosalind Franklin (1920–1958) and Maurice H. F. Wilkins (1916–2004).
On April 25, 1953, the journal, Nature, published an article by Francis Crick (1916–2004) and James Dewey Watson (born 1928) on the spatial structure of DNA. There was only one page of text, but it was with this publication that the era of Molecular biology began.