Nobel Prizes for magnetic resonance imaging and channel proteins

Jamie I Vandenberg and Philip W Kuchel

Medical Journal of Australia Vol 179 1/15 December 2003

“Discovery of aquaporins
We now know that channels that permit the selective flow of
water across cell membranes (aquaporins) are present in
almost all cells, but they were only definitively identified 15
years ago. Why did it take so long for them to be discovered?
In a sense it was because they are so difficult to measure and
because they are so common. Often the easiest way to
identify something is to compare two similar objects (in this
case, cells) and then determine what it is that is different
between them. This of course was not possible for water
channels, as almost all cells have them. In the late 1980s,
Peter Agre, while working on the rhesus blood group
antigens at Johns Hopkins University, US, serendipitously
discovered a new membrane protein that he called CHIP28
(channel integral membrane protein of molecular weight
28k). At the time he had no idea what it did.4 Previously and
independently, Gheorghe Benga and his group in Romania5
had shown that the water transport inhibitor p-chloromercuribenzoate
is selectively bound to a protein in red blood
cell membranes. Subsequent studies showed that this was a
glycosylated form of CHIP28.”

“References
1. Nobel e-Museum. Official website of the Nobel Foundation. Available at:
www.nobel.se (accessed Oct 2003).
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3. Mansfield P, Maudsley AA. Line scan proton spin imaging in biological structures
by NMR. Phys Med Biol 1976; 21: 847-852.
4. Denker BM, Smith BL, et al. Identification, purification, and partial characterization
of a novel Mr 28,000 integral membrane protein from erythrocytes and renal
tubules. J Biol Chem 1988; 263: 15634-15642.
5. Benga GH, Popescu O, Pop VI, Holmes RP. Chloromercuribenzenesulfonate
binding by membrane proteins and the inhibition of water transport in human
erythrocytes. Biochemistry 1986; 25: 1535-1538.
6. Preston GM, Carroll TP, Guggino WB, Agre P. Appearance of water channels
in Xenopus oocytes expressing red cell CHIP28 protein. Science 1992; 256:
385-387.”