STRUCTURE - ACTIVITY STUDIES OF AMINO ACIDS AND ACETYLCHOLINE IN CHEMORECEPTION OF THE STARFISH MARTHASTERIAS GLACIALIS

Publisher Summary This chapter discusses the structure–activity studies of amino acids and acetylcholine in the chemoreception of the starfish marthasterias glacialis. In a study, amino acids and some of their analogs were found to be chemical stimuli for taste buds and olfactory receptors in fishes. The ethological studies of chemoreception in sea stars demonstrated that the entire sequence of feeding motions can be triggered by amino acids as l -cysteine, l -proline, and some simple neutral amino acids. The concentration 3.3 × 10 −7 M was selected in structure–activity relationships studies of the substances triggering the appetitive feeding behavior. Relative stimulatory effectiveness was calculated in comparison with the l -cysteine response. In l -cysteine group of substances, the acetylation of the amino nitrogen, esterification in methyl esters, and the length of the carbon chain do not alter the stimulating properties. Changes in the sulfhydryl group reduce the effectiveness, while d -cysteine is nearly as effective as its l -isomer. It is also assumed that the sulfhydryl group plays a major role in l -cysteine response.