Tuesday, October 12, 1999
Nobel
Prize Awarded for Work on Protein
Functions Medicine New
York researcher's discovery has led to
breakthroughs in understanding several
genetic diseases. By
THOMAS H. MAUGH II, Times Medical
Writer A GERMAN American
researcher who discovered how the body
puts "addresses" on individual proteins so
that they arrive at the correct location
has been awarded the 1999 Nobel Prize for
medicine or physiology. The discoveries have helped scientists
unravel the causes of several genetic
diseases, including cystic fibrosis and
familial hypercholesterolemia, according
to the Nobel Foundation citation. Dr.
Günter Blobel of the Howard
Hughes Medical Institute at Rockefeller
University in New York City found that
each of the 1 billion protein molecules in
a single cell bears a short address tag.
The tag indicates that it belongs in the
nucleus, the cell membrane or elsewhere,
or that it should be secreted outside the
cell. With such tags, the cell runs like a
well-organized factory. Without them, it
would be like an earthquake-damaged
warehouse with cellular components
scattered uselessly about. When proteins are sent to the wrong
location by a defective tag, they cannot
perform their customary function and can
produce disease. In familial hypercholesterolemia, for
example, a very high level of cholesterol
occurs in the blood because proteins that
would normally remove it are not where
they should be. Understanding why that
happens, Blobel noted, is the first step
toward developing a treatment. The findings have also contributed to
the development of a more effective use of
cells as protein factories for the
production of important drugs. Blobel's work "has led to an explosion
of knowledge on the [movement] of
proteins in the cell, and even on the way
some kinds of drugs may be introduced into
cells," said Marvin Cassman,
director of the National Institute of
General Medical Sciences in Bethesda,
Md. Blobel, a
63-year-old native of
Waltersdorf, a city that was in
Germany when he was born but is now in
Poland, has worked in the United States
since the early 1960s and became a U.S.
citizen in the 1980s.He said Monday that
he will donate the $960,000 prize
toward the restoration of a synagogue
and the famed Frauenkirche
(Church of Our Lady) in
Dresden,
Germany, a city that was destroyed by
Allied firebombing in World War II when
he was 8. At a news conference, he
described viewing the city's skyline
just before the attacks began and later
after the terrible destruction had been
wrought. "It left a tremendous impression on
me," he said. Blobel is a founder of Friends of
Dresden, which has already raised more
than $1 million for restoration of
historic structures in the city. The tall scientist with a shock of
white hair said that when the phone call
from the Nobel Foundation came at 5 a.m.,
"I thought it might be a prank by one of
my colleagues. I slowly felt confident
this was real." After finally hanging up, he and his
wife, Laura, hugged each other, he
said. Blobel was cited for work that for the
first time explained how the internal
structure of cells is
maintained--particularly with respect to
proteins. Proteins are complex molecules,
composed of amino acids, that are the
primary building blocks for construction
of a cell. They also carry out chemical
reactions--such as the construction of
other proteins -- and serve as signaling
agents. Before Blobel's work, it was unknown
how newly made proteins were directed to
their correct locations in the cell and
how large proteins could traverse the
tightly sealed membranes surrounding
individual structures within the cell.
About the only thing that was known,
according to Dr. Donald Steiner of
the University of Chicago, was that newly
synthesized proteins were a little bit
longer than expected. Blobel speculated in 1971 that this
extra section of protein was a tag
signaling the protein's ultimate
destination. Over the next several years,
Steiner said, "he provided clear, elegant,
decisive experimental evidence that showed
exactly how this signal . . . was
functioning." Blobel's hypothesis and subsequent
proof of the concept was a seminal insight
into cellular functioning, added molecular
biologist Danny Schnell of Rutgers
University. "The rest of us have just come
along and filled in the details." The system has subsequently been shown
to be universal, functioning in plants,
animals and microorganisms as well as
humans. Blobel cautioned that his discoveries
do not have the immediate medical
implications of the work of some other
Nobel Prize winners. "It's not a cure for
AIDS, it's not a cure for Alzheimer's,"
Blobel said. "It's basic biological
research." But it does have implications for
medical research. Biotech companies now
add protein address codes to genes
inserted into yeast or bacteria for
producing drugs, so that the desired
product will be secreted by the
microorganism. |