Table 3.

Release of periplasmic proteins from CIAT899 by osmotic shock treatmenta

TreatmentProtein concn (μg of protein/ ml of extract)Alkaline phosphatase activity (nmol/min/ml of extract)bMalate dehydrogenase activity (nmol/min/ml of extract)c
Control cells0.5 (0.1)d 15 (0.8)0 (0)
Osmotically shocked cells54.5 (19.3)182 (15.6)0 (0)
Sonicated cells (control)354.3 (99.9)1,880 (99.2)321 (100)
Sonicated cells (shocked)228.6 (80.7)983 (84.4)284 (100)
  • a −Pi cells were shocked as described in the text. Control cells were treated like the shocked cells were treated, except that neither EDTA nor sucrose was used. The data are data from a single representative experiment.

  • b Nanomoles of p-nitrophenyl phosphate hydrolyzed per minute per milliliter of extract.

  • c Nanomoles of NADH oxidized per minute per milliliter of extract.

  • d The values in parentheses are percentages of the total cellular protein or enzyme activity.