ALTERATION OF COENZYME CONFORMATION IN THE COMPLEX OF ASPARTATE-AMINOTRANSFERASE WITH D-ASPARTATE

As the next step in X-ray crystallographic investigation of the comple x of chicken heart cytosolic aspartate transaminase with D-aspartate, we characterized the three-dimensional structure of the complex and th e changes therein with computer graphics. Interaction of the aspartate aminotransferase with D-aspartate was shown to alter the conformation of the coenzyme, pyridoxal 5'-phosphate (PLF), as follows: first, a s wing through 90 degrees in one of the subunits toward Arg-386 and Val- 37; second, a change of the dihedral PLF angles in both subunits.