Stability of soluble and extracellular vesicle-associated trypsin-like protease (TLP) activity of Bacteroides gingivalis W50.

Comparison was made of the specific activities of whole extracellular soluble protein (EP) and extracellular vesicle (ECV)-associated trypsin-like protease (TLP) activity from batch cultures of Bacteroides gingivalis W50. Rapid loss of activity occurred when these fractions were maintained at 37 degrees C in the presence of DTT. Residual levels of activity were detected after incubation of ECV and EP for up to 8 days under non-reducing conditions. Rates of activity loss in EP and ECV were similar. Mixtures of EP and ECV, in the same proportions as found in the culture supernatant showed neither depression nor elevation of total activity from the expected compound activities of the two separate fractions.