Identification of a Histidine Metal Ligand in the argE-Encoded N-Acetyl-L-Ornithine Deacetylase from Escherichia coli

Authors

Wade C. McGregor, Arizona State UniversityFollow
Danuta Gillner, Loyola University Chicago
Sabina I. Swierczek, Marquette UniversityFollow
Dali Liu, Loyola University ChicagoFollow
Richard C. Holz, Marquette UniversityFollow

Document Type

Article

Publication Date

2013

Source Publication

SpringerPlus

Source ISSN

2193-1801

Abstract

The H355A, H355K, H80A, and H80K mutant enzymes of the argE-encoded N-acetyl-L-ornithine deacetylase (ArgE) from Escherichia coli were prepared, however, only the H355A enzyme was found to be soluble. Kinetic analysis of the Co(II)-loaded H355A exhibited activity levels that were 380-fold less than Co(II)-loaded WT ArgE. Electronic absorption spectra of Co(II)-loaded H355A-ArgE indicate that the bound Co(II) ion resides in a distorted, five-coordinate environment and Isothermal Titration Calorimetry (ITC) data for Zn(II) binding to the H355A enzyme provided a dissociation constant (K_d) of 39 μM. A three-dimensional homology model of ArgE was generated using the X-ray crystal structure of the dapE-encoded N-succinyl-L,L-diaminopimelic acid desuccinylase (DapE) from Haemophilus influenzae confirming the assignment of H355 as well as H80 as active site ligands.

Comments

Published version. SpringerPlus, Vol. 2 (2013): 482-491. DOI. © 2013 McGregor et al.; licensee Springer. Used with permission. This is an Open Access article distributed under the terms of the Creative Commons Attribution License.

Recommended Citation

McGregor, Wade C.; Gillner, Danuta; Swierczek, Sabina I.; Liu, Dali; and Holz, Richard C., "Identification of a Histidine Metal Ligand in the argE-Encoded N-Acetyl-L-Ornithine Deacetylase from Escherichia coli" (2013). Chemistry Faculty Research and Publications. 294.
https://epublications.marquette.edu/chem_fac/294