Specificity of an amino acid‐sensitive cell in the adult Colorado beetle, Leptinotarsa decemlineata

Publisher Website
Google Scholar
Abstract
A single sensillum on each galea of adult Colorado beetles contains a cell which is highly sensitive to amino acids. The cell has a marked specificity for L‐alanine and γ‐amino butyric acid (GABA); other amino acids tested were at least 10 times less effective as stimulants. From a structure‐activity study, using compounds with longer and shorter carbon chains than GABA and longer chains than L‐alanine, it is apparent that the receptor is very sensitive to minor changes in these two stimulating molecules. It is argued that the receptor evolved in a form sensitive to L‐alanine, and that GABA is effective because it can bend into a configuration which mimics L‐alanine in terms of important active sites for the receptor system. This specific receptor for an important class of phagostimulants provides an opportunity for future studies in comparative receptor physiology.