Work

Isolation and Characterization of the Carbon–Phosphorus Bond-forming Enzyme Phosphoenolpyruvate Mutase from the MolluskMytilus edulis

Year: 1998

Type: article

Abstract: The enzyme phosphoenolpyruvate mutase was purified to homogeneity from the mollusk Mytilus edulis. The subunit size of the native homotetramer was determined to be 34,000 Da. The steady-state kinetic constants for catalysis of the conversion of phosphonopyruvate to phosphoenolpyruvate at pH 7.5 and 25 degrees C were measured at kcat = 34 s-1, phosphonopyruvate Km = 3 microM, and Mg2+ Km = 4 microM. The enzyme displayed a broad specificity for divalent metal ion activation; Co2+, Mn2+, Zn2+, and Ni2+ are activators, whereas Ca2+ is not. Analysis of the pH dependence of the Mg2+-activated mutase-catalyzed reaction of phosphonopyruvate revealed one residue that must be protonated (apparent pKa = 8.3) and a second residue that must be unprotonated (apparent pKa = 7.7) for maximal catalytic activity.

Source: Journal of Biological Chemistry

DOI: 10.1074/jbc.273.8.4443

Authors: Alexander Kim, Jaebong Kim, Brian M. Martin, Debra Dunaway-Mariano

Institutions: University of Maryland, College Park, National Institute of Mental Health

Language: English

Topic: Biochemical and Molecular Research

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: hybrid

Estimated APC paid: $3,430

Funder: National Institute of General Medical Sciences