FATTY-ACID BINDING-PROTEIN IN FLIGHT-MUSCLE OF THE LOCUST, SCHISTOCERCA-GREGARIA

The cytosol of flight muscle from the adult desert locust, Schistocerca gregaria, contains a fatty acid binding protein (FABP). Locust FABP has a molecular weight of 15000 and an isoelectric point of 5.2. It binds fatty acids stoichiometrically in a 1:1 ratio. Its molecular characteristics, tissue specificity and electrophoretic behavior are reminiscent of mammalian M-FABP. Compared to its mammalian counterpart, the cytosolic concentration is much higher, reflecting the high rate of fatty acid oxidation observed during locust flight. Our discovery, showing for the first time an FABP in an invertebrate species, supports the proposed function of muscle FABP as intracellular fatty acid receptor or transport protein.