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THE SYNTHESIS 

 OF PROTEINS* 



Mahlon B. Hoagland 



MASSACHUSETTS GENERAL HOSPITAL 



Galileo, at the end of his great work, Discourses Concerning Two New 

 Sciences, wrote: "The door is now opened, for the first time, to a new 

 method, fraught with numerous and wonderful results which in future 

 years will command the attention of other minds." Workers in molecu- 

 lar biology today often find themselves experiencing a similar sense 

 of awed awareness that doors are opening and that their new methods 

 afford impressive power to explore what lies beyond. The discovery of 

 bacterial transformation, the postulation and growing experimental 

 verification of the structiu-e of DNA, the deepening understanding of 

 bacterial and viral genetics and of the specific influence of mutation on 

 protein structure, and the increased understanding of the mechanism 

 of nucleic acid and protein biosynthesis— these are exciting manifesta- 

 tions of a new era. 



Protein may be said to be the ultimate expression of the genetic 

 information residing in DNA, and an understanding of the mechanism 

 by which DNA governs its synthesis is the goal of much of today's work 

 in molecular biology. Generally, there are two broad ways of attacking 

 the problem. One may examine natural or artificially induced altera- 

 tions in an organism's DNA and note the resulting changes in the con- 

 stitution of its protein, obtaining increasingly refined structural cor- 

 relations. Or one may tiy to tease out the individual chemical cnents 

 along the path of protein synthesis. The first approach starts from the 



* Based on studies supported by grants from the U.S. Public Health Service, 

 the U.S. Atomic Energy Commission, and the American Cancer Society. Publica- 

 tion No. 1041 of the Cancer Commission of Harvard University. 



