EFFECTS OF ATP ON THE INTERACTION OF ALBUMIN AND ITS C-TERMINAL AMINO-ACID L-ALANINE WITH THE SUGAR RECEPTOR CELL IN PROTOPHORMIA-TERRAENOVAE (DIPTERA, CALLIPHORIDAE)

Stimulation with bovine serum albumin (BSA) and its C-terminal amino a cid L-alanine evokes spike activity from the ''sugar'' cell of the lab ellar chemosensilla in Protophormia. The presence of ATP in the BSA so lution strongly enhances this effect, but is pH-dependent. On the cont rary, addition of ATP to the L-alanine solution inhibits the ''sugar'' cell response regardless of pH. Reception mechanisms for BSA and L-al anine are discussed.