Comparative evaluation of mitogenicity and basement-membrane-degrading activity of Pseudomonas aeruginosa slime glycolipoprotein and alginate.

Alginate from a heavily mucoid Pseudomonas aeruginosa strain and slime glycolipoprotein obtained from the revertant nonmucoid variant of the mucoid strain were tested for mitogenic activity on human peripheral lymphocytes and for degradation of 3H-labeled basement membranes of the anterior lens capsule of bovine eyes. Slime glycolipoprotein exerted mitogenic activity in concentrations from 50 to 200 micrograms/ml, whereas alginate was not mitogenic as shown by [3H]thymidine uptake. Alginate did not show any basement membrane degradation, whereas slime glycolipoprotein exhibited basement-membrane-degrading activity from 35 to 450 micrograms/ml in a dose-related manner. This activity was inhibited by metal chelators but not thiol protease inhibitors. The results suggest that alginate lacks the mitogenic and biodegrading activities of slime glycolipoprotein; these activities nevertheless need further investigation.