Edman, Pehr

Eclipsed conformation, 94 molecular model of, 94 Edman, Pehr Victor, 1031 Ed man degradation, 1031-1032 mechanism of. 1032 Eicosanoid, 1067-1070... 

Edman, Pehr Victor (1916-1977), a pioneer in the field of peptide and protein chemistry. Already for his Ph.D he had isolated and purified angiotensin. In 1947, he accepted an associate professorship at the University of Lund (Sweden), and in 1957 Edman came to Melbourne as the first John Holt director of research at St. Vincent s School of Medical Research. In 1972, he moved to Germany, having been appointed Professor at the Max-Planck-Institute for Biochemistry at Martinsried. He is the inventor of an important method for protein structure determination, named the Edman degradation [F. J. Morgan, Edman, Pehr Victor (1916-1977), Austr. Diet. Biograph. 1996, Volume 14, pp. 78-79]. 

Edman, Pehr Victor, 1916-1977 (pp. 118,240, Plate 15) born in Stockholm in 1916, matriculation examination in 1935, studied medicine at the Karolinska Institute Medical School in Stockholm from 1935, Bachelor of Medicine in 1938, graduation as a physician in 1946. Concurrently with his studies in medicine he started his training in biochemistry with Erik Jorpes, for a short time also with Hugo Theorell, and soon started a project on angiotensin that led to a MD thesis. Then he widened his experience in protein chemistry during one year at the Rockefeller Institute in Princeton with Northrop and Kunitz (crystallization of proteolytic enzymes). On his return to Sweden, Edman was awarded an associate professorship in Lund in 1947 where he conducted his stepwise peptide degradation work (p. 118) between 1950 and 1956. In 1957 Pehr Edman accepted an offer to be Director of Research at St. Vincent s School of Medical Research in Melbourne, Australia, where he remained for 15 years, during which the work on an automated sequence analyzer was finished in 1967. From 1972 until his death from a brain tumor in 1977 he was Director of the Department of Protein Chemistry of the Max-Planck-Institute for Biochemistry in Martinsried near Munich. 

A major advance was devised by Pehr Edman (University of Lund Sweden) that has become the standard method for N terminal residue analysis The Edman degrada tion IS based on the chemistry shown m Figure 27 12 A peptide reacts with phenyl iso thiocyanate to give a phenylthwcarbamoyl (PTC) denvative as shown m the first step This PTC derivative is then treated with an acid m an anhydrous medium (Edman used mtromethane saturated with hydrogen chloride) to cleave the amide bond between the N terminal ammo acid and the remainder of the peptide No other peptide bonds are cleaved m this step as amide bond hydrolysis requires water When the PTC derivative IS treated with acid m an anhydrous medium the sulfur atom of the C=S unit acts as... 

To sequence an entire polypeptide, a chemical method devised by Pehr Edman is usually employed. The Edman degradation procedure labels and removes only the amino-terminal residue from a peptide, leaving all other peptide bonds intact (Fig. 3-25b). The peptide is reacted with phenylisothiocyanate under mildly alkaline conditions, which converts the amino-terminal amino acid to a phenylthiocarbamoyl (PTC) adduct. The peptide bond next to the PTC adduct is then cleaved in a step carried out in anhydrous trifluo-roacetic acid, with removal of the amino-terminal amino acid as an anilinothiazolinone derivative. The deriva-tized amino acid is extracted with organic solvents, converted to the more stable phenylthiohydantoin derivative by treatment with aqueous acid, and then identified. The use of sequential reactions carried out under first basic and then acidic conditions provides control over... 

Pehr Edman Univ. of Lund, Sweden protein degradation developed... 

This problem was overcome by Pehr Edman who devised a method for labeling the N-terminal residue and then cleaving it from the rest of the peptide without breaking the peptide bonds between the other amino acids. In so-called... 

Pehr Victor Edman (1916 1977) was born in Stockholm, Sweden, and received an M.D. in 1946 at the Karolinska Institute, After a year in the United States at the Rockefeller Institute, he returned to Sweden as professor at the University of Lund. In 1957, he moved to St. Vincent s School of Medical Research in Melbourne, Australia, where he developed and automated the method of peptide sequencing that bears his name. A reclusive man, he never received the prizes or recognition merited by the importance of his work. 

In its various modifications, however, the most widely used method of N-terminal residue analysis is one introduced in 1950 by Pehr Edman (of the University of Lund, Sweden). This is based upon the reaction between an amino group and phenyl isothiocyanate to form a substituted thiourea (compare Sec. 32.7). Mild hydrolysis with hydrochloric acid selectively removes the N-terminal residue as the phenylthiohydantoin, which is then identified. The great advantage of this... 

As of this writing, 50 years have passed since Pehr Edman published his first note on chemical degradation of peptide chains, A Method for the Determination of the Amino Acid Sequence in Peptides. As testament to the continuing relevance of this technique, the following job announcement was recently posted. 

In the tradition of their N-terminal compatriot Pehr Edman, these researchers have aheady been working on C-terminal sequencing for years and they have C-terminally sequenced hundreds of proteins and peptides. You should take advantage of the enthusiasm of these aficionados. If you don t get an3rwhere with your sample, why don t you call them in Stockholm and ask them for a run in the optimized C-terminal sequencer You have nothing to lose. 

Decisive progress in stepwise degradation was brought about by Pehr Edman (Plate 15) in 1950 [11], who found that phenylisothiocyanate, the sulfur analog of Bergmann s reagent, reacts with the N-terminal amino group at pH 9 even at room temperature, and that the thioureido compound hereby formed is readily split by weak acids, e.g. trifluoroacetic acid, to yield a 2-anilinothiazolin-5-one. 

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