Rodney Porter Biography (1917-1985)
Rodney Robert Porter was born October 8, 1917, in Newton-le-Willows, near Liverpool in Lancashire, England. His mother was Isobel Reese Porter and his father, Joseph L. Porter, was a railroad clerk. He attended Liverpool University, where he earned a B.S. in biochemistry in 1939. During World War II he served in the Royal Artillery, the Royal Engineers, and the Royal Army Service Corps, and participated in the invasions of Algeria, Sicily, and Italy. After his discharge in 1946, he resumed his biochemistry studies at Cambridge University under the direction of Frederick Sanger.
Porter's doctoral research at Cambridge was influenced by Nobel laureate Karl Landsteiner's book, The Specificity of Serological Reactions,which described the nature of antibodies and techniques for preparing some ofthem. Antibodies, at the time, were thought to be proteins that belonged toa class of blood-serum proteins called gamma globulins. From Sanger, who hadsucceeded in determining the chemical structure of insulin (a protein that metabolizes carbohydrates), Porter learned the techniques of protein chemistry.Sanger had also demonstrated tenacity in studying problems in protein chemistry involving amino acid sequencing that most believed impossible to solve, and he was a model for the persistence Porter would show in his later work onantibodies.
Fortunately, Porter chose rabbits to experiment on for his research. Althoughthis was not known at the time, the antibody system is not as complex in this animal as it is in some. The most important antibody, or immunoglobulin, inthe blood is called IgG, which contains more than 1,300 amino acids. The problem of discovering the active site of the antibody--the part that combines with the antigen--could be solved only by working with smaller pieces of the molecule. Porter discovered that an enzyme from papaya juice, called papain, could break up IgG into fragments that still contained the active sites but were small enough to work with. He received his Ph..D. for this work in 1948.
Porter remained at Cambridge for another year, then in 1949 he moved to the National Institute for Medical Research at Mill Hill, London. There, he improved methods for purifying protein mixtures and used some of these methods to show that there are variations in IgG molecules. He obtained a purer form of papaya enzyme than had been available at Cambridge and repeated his earlier experiments. This time the IgG molecules broke into thirds, and one of these thirds was obtained in a crystalline form which Porter called fragment crystallizable (Fc).
Obtaining the Fc crystal was a breakthrough; Porter now was able to show thatthis part of the antibody was the same in all IgG molecules, since a mixtureof the different molecules would not have formed a crystal. He also discovered that the active site of the molecule (the part that binds the antigen) wasin the other two-thirds of the antibody. These he called fragment antigen-binding (or FAB) pieces. After Porter's research was published in 1959, anotherresearch group, led by Gerald M. Edelman at Rockefeller University in New York, split the IgG in another way--by separating amino acid chains rather thanbreaking the proteins at right angles between the amino acids as Porter's papain had done.
In 1960 Porter was appointed professor of immunology at St. Mary's Hospital Medical School in London. There he repeated Edelman's experiments under different conditions. After two years, having combined his own results with those of Edelman, he proposed the first satisfactory structure of the IgG molecule.The model, which predicted that the FAB fragment consisted of two different amino acid chains, provided the basis for far-ranging biochemical research. Porter's continuing work contributed numerous studies of the structures of individual IgG molecules. In 1967 Porter was appointed Whitley Professor of Biochemistry and chairman of the biochemistry department at Oxford University. Inhis new position, Porter continued his work on the immune response, but his interest shifted from the structure of antibodies to their role as receptors on the surface of cells. To further this research, he developed ways of tagging and tracing receptors. He also became an authority on the structure and genetics of a group of blood proteins called the complement, which binds the Fcregion of the immunoglobulin and is involved in many important immunologicalreactions.
Porter was killed in an automobile accident a few weeks before he was to retire from the Whitley Chair of Biochemistry. He had been planning to continue as director of the Medical Research Council's Immunochemistry Unit for anotherfour years; he had also intended to continue his laboratory work, attemptingto crystallize one of the proteins of the complement system.