Mahlon Hoagland on Growing Interest in Protein Synthesis and Amino Acid Activation
  Mahlon Hoagland     Biography    
Recorded: 08 Jun 2006

I was fortunate to be in the same laboratory where Paul Zamecnik and his associates were working on protein synthesis. It was a time when we were just beginning to learn that the ribosome was key in protein synthesis by cellular fractionation processes; that soluble enzymes were necessary for protein synthesis. That there was an energy requirement, namely ATP [Adenosine triphosphate] was needed to get the protein to be made using—studying it with radioactive amino acids in the test tube.

After working on the beryllium project I left the Zamecnik laboratory though knowing these things were going on and wanting to come back to work on them, but feeling I needed more training in biochemistry. So I spent a year in Copenhagen with Karl Linderstrom-Lang, a noted physical chemist and then came back and spent another year with Fritz Lipmann in the Mass General hospital laboratories right next door to us.

With Lipmann I learned how to use certain techniques which helped me three months later when I got back to join the Zamecnik group to study the mechanism of amino acid activation and protein synthesis. It was understood at the time—this was about 1953 or 1952. I t was understood at the time that amino acids had to be activated, that is energized using ATP in order participate in the synthesis of the polypeptide or poly amino acid chain. So within a relatively short time of visiting Zamecnik—coming to Zamecnik’s lab and having visited with Lipmann for a year, I used techniques I learned in Lipmann’s lab to discover the mechanism of amino acids activation. So that was the beginning of my interaction—

With the Zamecnik group.

Mahlon Hoagland, a molecular biologist who was one of the discoverer of the transfer ribonucleic acid - tRNA. He received a medical degree from Harvard Medical School in 1948. He served as a doctor during the Second World War. When the War ended he returned to Harvard and became researcher in the Huntington Laboratories at the Massachusetts General Hospital in Boston. He worked in the bacteriology and immunology department of Harvard Medical School from 1952 till 1967.

Working together with Paul Zamecnik and Elizabeth Keller he discovered the initial steps of protein synthesis. Two years later in 1958 Hoagland and Zemecnik discovered tRNA. His main input to the laboratory was in his work with amino acid activating enzymes. He noticed that certain enzymes were required to activate amino acids so they could combine with tRNA molecules and eventually be incorporated into new protein molecules. These enzymes were named aminoacyl tRNA synthetases.

In 1957 Hoagland moved to Cambridge where he worked for a year with Crick at Cambridge University. Working together they tried to explain the genetic code. He was Associate Professor of Microbiology at Harvard Medical School and in 1967 was appointed professor in the biochemistry department at the Dartmouth Medical School. After 3 years he left Dartmouth and became Director and President of the Worcester Foundation for Experimental Biology in Massachusetts. He retired in 1985.

Mahlon Hoagland was awarded the Franklin Medal for life science. He was a member of the American Academy of Arts and Sciences and the US National Academy of Sciences. He died on September 19, 2009.

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