Erwin Chargaff Essays - Genetics, Nucleobases, Nucleic Acids

Erwin Chargaff Erwin Chargaff, born 1905 in Czernowiz, Austria, was a pioneer in biochemistry contributing to the understanding of DNA. He, in 1928, earned his doctoral degree in chemistry at the University of Vienna's Spath's Institute in 1928. Erwin began his career in biochemistry at Yale University, working under Rudolph J. Anderson from 1928 to 1930. His early work included stories of the complex lipids, the fats or fatty acids that occur in microorganisms. Helping discover the unusual fatty acids and waxes in acid-fast mycobacteria led him to study the metabolism and biological role of lipids in the body. Chargaff was also a pioneer in the use of radioactive isotopes of phosphorus as a tool to study in the synthesis and breakdown of phosphorus-containing lipid molecules in living cells. He published a paper on the synthesis of a radioactive organic compound called alpha-glycerophosphoric acid. He began to study nucleic acids in 1944, while at Colombia. Until this time scientists believed that amino acids carried genetic information. DNA was also believed to contain the tetranucleotides made up of cytosine, thymine, adenine and guanine, that served as an attachment site for the amino acids that made up genes. It was already known that a cell's nucleus is comprised in part by DNA, Chargaff was able to determine how much of which bases were present by measuring the amount of light each quantity of base absorbed. He showed that adenine and thymine occur in DNA in equal proportions in all organisms and that cytosine and guanine are also found in equal quantities. Chargaff's major conclusion is that DNA carries genetic information, and the number of different combinations in which the four nucleic acids appear in DNA provides enough complexity to form the basis of heredity. Finally, he concluded that the identity of combinations differs from species to species and that DNA strands differ from species. Overall, his findings were important contributions in biochemistry, including the addition of a key piece in the puzzle of the structure of DNA. This all led to major developments in the field of medical genetics, and, ultimately helped pave the way for gene therapy and the birth of the biotechnology industry.