CYANIDE BINDING AND HEME CAVITY CONFORMATIONAL TRANSITIONS IN DROSOPHILA MELANOGASTER HEXA-COORDINATE HEMOGLOBIN 2G3H TRANSPORT PROTEIN, DROSOPHILA MELANOGASTER HEMOGLOBIN STRUCTURE; HEXA- COORDINATE HEMOGLOBIN; CYANIDE BINDING TO HEMOGLOBIN; HEME DISTAL SITE STRUCTURE; FRUIT FLY HEMOGLOBIN