Frederick Sanger
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Frederick
Sanger, OM, CH, CBE, FRS (born 13 August 1918) is an English biochemist
and twice a Nobel laureate in chemistry. He is the fourth (and only
living) person to have been awarded two Nobel Prizes in Chemistry
(1958, 1980)
Sanger was born in Rendcomb, a small village in
Gloucestershire, the second son of Frederick Sanger, a medical
practitioner, and his wife, Cicely. He was born on August 13, 1918, and
educated at The Downs School (Herefordshire) and Bryanston School and
then completed his Bachelor of Arts in natural sciences from St John's
College, Cambridge in 1939. Raised as a Quaker, he learned to abhor
violence, and during the Second World War he was a conscientious
objector, being allowed to continue his research for a Ph.D.
He
originally intended to study medicine, but became interested in
biochemistry; some of the leading biochemists in the world were at
Cambridge at the time. He completed his Ph.D. in 1943 under A.
Neuberger, on lysine metabolism and a more practical problem concerning
the nitrogen of potatoes.
Sanger's first triumph was to
determine the complete amino acid sequence of the two polypeptide
chains of insulin in 1955.[citation needed]. Prior to this it was
widely assumed that proteins were somewhat amorphous. In determining
these sequences, Sanger proved that proteins have a defined chemical
composition. For this purpose he used the "Sanger Reagent",
fluorodinitrobenzene (FDNB), to react with the exposed amino groups in
the protein and in particular with the N-terminal amino group at one
end of the polypeptide chain. He then partially hydrolysed the insulin
into short peptides (either with hydrochloric acid or using an enzyme
such as trypsin). The mixture of peptides was fractionated in two
dimensions on a sheet of filter paper: first by electrophoresis in one
dimension and then, perpendicular to that, by chromatography in the
other. The different peptide fragments of insulin, detected with
ninhydrin, moved to different positions on the paper, creating a
distinct pattern which Sanger called “fingerprints”. The peptide from
the N-terminus could be recognised by the yellow colour imparted by the
FDNB label and the identity of the labelled amino acid at the end of
the peptide determined by complete acid hydrolysis and discovering
which dinitrophenyl-amino acid was there. By repeating this type of
procedure Sanger was able to determine the sequences of the many
peptides generated using different methods for the initial partial
hydrolysis. These could then be assembled into the longer sequences to
deduce the complete structure of insulin. Sanger's principal conclusion
was that the two polypeptide chains of the protein insulin had precise
amino acid sequences and, by extension, that every protein had a unique
sequence. It was this achievement that earned him his first Nobel prize
in Chemistry in 1958. This discovery was crucial for the later sequence
hypothesis of Crick for developing ideas of how DNA codes for proteins.
In
the 1960s he turned his attention to RNA molecules and again developed
methods for separating fragments of these generated with specific
nucleases. In the course of this he discovered in 1964, with Kjeld
Marcker, the formylmethionine tRNA which initiates protein synthesis
(in bacteria; this is closely related to the initiator methionine tRNA
which was later discovered in eukaryotes). By 1967 he had determined
the nucleotide sequence of the 5S ribosomal RNA from Escherichia coli,
a small RNA about 115 nucleotides long. He then turned to DNA and, by
1975, had developed the “dideoxy” method for sequencing DNA molecules,
also known as the Sanger method.[1] Two years later Sanger used his
technique to successfully sequence the genome of the Phage Φ-X174; the
first fully sequenced DNA-based genome. He did this entirely by hand.
This has been of key importance in such projects as the Human Genome
Project and earned him his second Nobel prize in Chemistry in 1980,
which he shared with Walter Gilbert and Paul Berg. He is thus far
(2009) the only person to have been awarded two Nobel Prizes in
Chemistry, and one of only four two-time Nobel laureates: the other
three were Marie Curie (Physics, 1903 and Chemistry, 1911), Linus
Pauling (Chemistry, 1954 and Peace, 1962) and John Bardeen (twice
Physics, 1956 and 1972). In 1979, he was awarded the Louisa Gross
Horwitz Prize from Columbia University together with Walter Gilbert and
Paul Berg.
Sanger's techniques used random distributions to get
ordered sequence. The homochromatography was made from randomized RNA
polymers. The plus-minus sequencing system used the random termination
of polymerase to get a population of DNA polymers of each size. The
dideoxy system took advantage of the random insertion of dideoxy
nucleotides at every sequence position. The ordering of the phi X 174
genome used random shot-gun sequencing (later employed by Venter) and
then closing the sequence circle by computer alignment. Professor
Pieczenik used Sanger logic i.e. random distribution of nucleotides to
create the first combinatorial libraries of peptides.
http://www2.mrc-lmb.cam.ac.uk/archive/g_pieczenik.html
Sanger
retired in 1983 to his home, “Far Leys”, in Swaffham Bulbeck outside
Cambridge where he became an avid gardener. Adjacent to his extensive
garden is “Sanger Wood”. In 1992, the Wellcome Trust and the Medical
Research Council founded the Sanger Centre (now the Sanger Institute),
named after him. The Sanger Institute, located near Cambridge, England,
is one of the world's most important centres for genome research and
played a prominent role in sequencing the human genome.
Almost his
only public utterance in two decades was to put his name to a letter by
other UK Nobel laureates protesting about the Iraq war. Referring to
his youthful conscientious objection, he said, "I still hate war. That
is why I signed that letter".
In 2007 the British Biochemical
Society was given a grant by the Wellcome Trust to catalogue and
preserve the 35 laboratory notebooks in which Sanger recorded his
remarkable research from 1944 to 1983. In reporting this matter,
Science magazine noted that Sanger, "the most self-effacing person you
could hope to meet", now was spending his time gardening at his
Cambridgeshire home.