Catalytic properties of the PepQ prolidase from Escherichia coli. Academic Article uri icon

abstract

  • The PepQ prolidase from Escherichia coli catalyzes the hydrolysis of dipeptide substrates with a proline residue at the C-terminus. The pepQ gene has been cloned, overexpressed, and the enzyme purified to homogeneity. The k(cat) and k(cat)/K(m) values for the hydrolysis of Met-Pro are 109 s(-1) and 8.4 x 10(5)M(-1)s(-1), respectively. The enzyme also catalyzes the stereoselective hydrolysis of organophosphate triesters and organophosphonate diesters. A series of 16 organophosphate triesters with a p-nitrophenyl leaving group were assessed as substrates for PepQ. The S(P)-enantiomer of methyl phenyl p-nitrophenyl phosphate was hydrolyzed with a k(cat) of 36 min(-1) and a k(cat)/K(m) of 710 M(-1)s(-1). The corresponding R(P)-enantiomer was hydrolyzed more slowly with a k(cat) of 0.4 min(-1) and a k(cat)/K(m) of 11 M(-1)s(-1). The PepQ prolidase can be utilized for the kinetic resolution of racemic phosphate esters. The PepQ prolidase was shown to hydrolyze the p-nitrophenyl analogs of the nerve agents GB (sarin), GD (soman), GF, and VX.

published proceedings

  • Arch Biochem Biophys

author list (cited authors)

  • Park, M., Hill, C. M., Li, Y., Hardy, R. K., Khanna, H., Khang, Y., & Raushel, F. M.

citation count

  • 26

complete list of authors

  • Park, Min-Sun||Hill, Craig M||Li, Yingchun||Hardy, R Kristoffer||Khanna, Hemant||Khang, Yong-Ho||Raushel, Frank M

publication date

  • January 2004