DESIGN, CREATION, AND CHARACTERIZATION OF A STABLE, MONOMERIC TRIOSEPHOSPHATE ISOMERASE

Protein engineering on trypanosomal triosephosphate isomerase (TIM) co nverted this oligomeric enzyme into a stable, monomeric protein that i s enzymatically active. Wild-type TIM consists of two identical subuni ts that form a very tight dimer involving interactions of 32 residues of each subunit. By replacing 15 residues of the major interface loop by another 8-residue fragment, a variant was constructed that is a sta ble and monomeric protein with TIM activity. The length, sequence, and conformation of the designed fragment were suggested by extensive mod eling.