Meeting Abstract
The terrestrial slug Arion subfuscus produces a remarkably tough defensive secretion. This dilute gel adheres strongly to anything that touches the slug. The glue is stiff, yet highly extensible. A bioinspired glue based on this secretion was recently developed that greatly exceeds the performance of any currently available medical glues. To analyze the slug glue further, RNA-Seq and tandem mass spectrometry were used to characterize all the proteins in the glue. Most of the proteins were either matrilin-like or lectin-like. The lectin-like proteins are particularly interesting because they make up almost half of the total protein, and they play a central role in glue function. They are relatively small, basic proteins. RNA-Seq found that the lectin-like proteins consist of eleven abundant C-lectins, C1q domain containing proteins, and H-lectins. They shared essential conserved residues, but each typically only had 30-50% sequence identity with any other protein in this group. The ability of these proteins to form hetero-oligomers was tested using native gel electrophoresis and tandem mass spectrometry. Size exclusion chromatography was used to quantify the size of complexes. These experiments found evidence that the C-lectins and C1q-containing proteins form heterotrimers and heterodimers respectively. Each subunit likely has a different binding specificity, making them versatile linking agents.
