Spring 1995 Volume 4, Number 2
A
"smart-bomb" for brain proteins
Proteins do the lion's share of work in the brain: They make up most
of the brain's chemical messengers, actas receptors for those messengers, and form up as parts in brain cells'
structures. Not surprisingly, proteins are vastly interesting to brain
researchers, and strategies are fervently desired to inactivate chosen proteins
at precise times and sites in neurons
CALI targets light energy to generate very short-lived free radicals that locally damage the bound
protein. (Photo by Dr. Jay)
- thus revealing what the protein
contributed before it was lost. Daniel Jay and his colleagues at Harvard
University have developed a kind of "smart bomb" for brain proteins -
"chromophore assisted laser inactivation (CALI)" - that has been able to
inactivate 90 percent of the proteins tried. Using a dye to label an antibody
for a chosen protein and then allowing the dyed antibody to bind the protein,
they shoot it with a laser light. The light is absorbed by the dye, setting off
a reaction that destroys the protein without damaging the cell. A refinement,
Micro-CALI, can inactivate proteins within a chosen region of a single cell,
allowing the roles of specific proteins during neural development to be
determined. Now Jay's lab is using Micro-CALI to find out how axons grow and
read their environment in order to correctly wire up the nervous system.
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