Effect of solute hydrogen bonding capacity on osmotic stability of lysosomes.

The effect of solute hydrogen bonding capacity on the osmotic stability of lysosomes was examined through measurement of free enzyme activity of lysosomes after their incubation in sucrose and poly(ethylene glycol) (PEG) (1500-6000 Da molecular mass) media. Free enzyme activity of the lysosomes was less in the PEG medium than that in the sucrose medium under the same hypotonic condition. The lysosomal enzyme latency loss decreased with increasing hydrogen bonding capacity of the solute. In addition, the lysosomes lost less latency at lower incubation temperature. The results indicate that solute hydrogen bonding capacity plays an important role in the osmotic protection of an incubation medium to lysosomes.