TABLE 1

Kinetic constants and specific activities for hydrolysis of (+)-γ-lactam by (+)-γ-lactamases from different microorganisms

CatalystaKm (mM)bkcat (s−1)bSp act (U/mg)Reference
γlacBJ0.71.81507
γlacAP1117.826.38
γlacSS17.8NR24.615
γlacSS-II53NR20.615
γlacMHNRNR253.56
MhIHL122002,52031
  • a γlacBJ, (+)-γ-lactamase from Bradyrhizobium japonicum; γlacAP, (+)-γ-lactamase from Aeropyrum pernix; γlacSS, (+)-γ-lactamase from Sulfolobus solfataricus; γlacSS-II, type II (+)-γ-lactamase from S. solfataricus; γlacMH, (+)-γ-lactamase from M. hydrocarbonoxydans; MhIHL, (+)-γ-lactamase in this study. One unit of enzyme activity was defined as the amount of enzyme that catalyzed the conversion of 1 nM substrate per minute.

  • b NR, not reported.