Poster 30: DapE-Encoded N-Succinyl-l,l-Diaminopimelic Acid Desuccinylase (DapE) plays an integral role in the biosynthesis of lysine (Lys) and meso-diaminopimelic acid. The full-scan Magnetic Circular Dichroism (MCD) spectra of DapE from both Haemophilus influenza and Neisseria meningitides confirms that metal at the high affinity site of this enzyme is 4-coordinate. The Variable Temperature Variable Field (VTVH) study of DapE from both species suggests that the bridging ligand between the two metals is water. The addition of captopril, an inhibitor of DapE, into the enzyme from both species shows similar results with a shift in the four-coordinate peak. This shift indicates antiferromagnetic coupling at the active site. The addition of DTT shows similar results as seen in those from the addition of captopril, but the antiferromagnetic coupling was even stronger. However, an additional peak at 700 nm was found only in the full scan of HiDapE with DTT, suggesting additional interactions of DTT with HiDapE active site which was absent in NmDapE.
