past_research

Past Research Matt Brock discovered that a commonly used biochemical reagent (dithiothreitol or DTT) could be induced to bind to nitric oxide (itself a powerful regulator of important proteins) and that this new molecule was an effective and highly unusual potassium-channel blocker. In fact, of the hundreds of known blockers, DTT·NO is the only one that has such a simple chemical structure with no electrical charge. Jon Sack, in collaboration with colleagues at the University of Illinois, isolated a novel toxin from a defensive mucous secretion of a local kelp-forest snail (the channeled top-snail, Calliostoma canaliculatum) and identified its chemical structure, which is quite similar to that of serotonin, a neurotransmitter in human brain. Sack's toxin does not perturb potassium channels by blocking them, but rather does so by holding them closed, so that they cannot open properly. It is the only organic molecule that is known to act in this way. Matt is presently doing a post-doc at NASA-Ames, and Jon is continuing at Stanford in Rick Aldrich's lab in the Medical School. Joseph Schulz worked on cone snails, one of the sea's slowest creatures, which yet may be its fastest hunter. His study reveals that the fish-hunting cone snail immobilizes passing fish by firing a harpoonlike tooth at them. The entire process--from detecting the prey to stunning it--takes less than 300 milliseconds, making it one of the quickest captures known. Joseph worked on the nature of the toxin in tropical species. By using HPLC and software written here at Hopkins, he is narrowing in on the exact peptide sequence and modifications that make the toxin do its deadly work. Cone Snails and a light microscope image of one of the harpoons used to stun prey. See Science Now article [subscription required]

"How do squids communicate by changing colours on the surface of their skin? Working with Andrew Packard (Naples and France) he is uncovering unsuspected subtleties in the way the famous flashing cells function." See video pdf

Working with Thomas Preuss a while back yielded information on behavioural development in baby squid. See Stanford Report March 29, 2000 and Stanford News March 22, 2000. In 1997 Gilly worked with Rhanor Gillette from the University of Illinois to try and understand why the sodium channels in the brains of squids were so much faster than the ones in another mollusk, the limpet. "Squids evolved from quite sluggish mollusks into somewhat faster, swimming shell-wearing polyps, like the chambered Nautilus that bob around in the abyss. Then squid went on to the sleek modern versions that hunt in packs." See Stanford News June 3, 1997 and http://news-service.stanford.edu/news/1997/may21/squid.html. Projects funded in part by the National Science Foundation

Gilly Lab