2Graduate School, Chinese Academy of Sciences, Beijing 100039, PR China
3School of Physical Science and Technology Sichuan University, Chengdu 610064, PR China
* To whom correspondence should be addressed.
Received December 15, 2008; Revision received February 19, 2009
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.
KEY WORDS: hydrogen bonding capacity, lysosomal osmotic stability, lysosome