title: [Research on enzymes of Mycoplasma: enolase of Mycoplasma hominis].
abstract: A screening of enzymes on cell-free extracts of various species of mycoplasmas revealed the presence of enolase (EC 4.2.1.11) in significative amount in M. pneumoniae and M. fermentans, in lower amounts in M. hominis, A. laidlawii and in trace only in U. urealyticum. The value of activity of the various mycoplasmas could be correlated with their metabolism. From 40 g of cell paste of M. hominis, 2.5 mg of enolase purified over 70 folds, was obtained with successive steps of salt fractionation and column chromatography. Kinetic studies gave the following constants: Km for 2-phospho-D-glicerate, 0.7 x 10(-4)M; optimum of Mg++ concentration, 1 x 10(-3)M; optimum of pH, 7.7 inhibition by fluoride and phosphate, I = 0.77 X 10(-12)M4. Molecular weight estimation indicated for the native enzyme a value of about 100,000 daltons. These data suggest closer similarities with the enolase of microorganisms like E. coli and yeast than with the genus Thermus or B. stearothermophilus.
mesh_terms: D009174:Mycoplasma / Q000201:enzymology*; D010751:Phosphopyruvate Hydratase / Q000032:analysis*
chemical_list: D010751:Phosphopyruvate Hydratase
vernacular_title: Ricerche sugli enzimi dei micoplasmi: enolasi del Mycoplasma hominis