Differential expressions and activities of the cysteine proteinases of cellular slime molds (Dictyostelium discoideum, Polysphondylium pallidum).

In the present study the differential expression of the cysteine proteinases (CPs) has been examined in detail for two slime molds i.e., the AX3 strain of Dictyostelium discoideum and the WS320 strain of Polysphondylium pallidum. Lipopolysaccharide (LPS) and peptidoglycan both components of the bacterial cell wall were tested for the CPCF activity. Additionally the effects of the presence bacterial components on the germination kinetics were examined. This study shows that peptidoglycan is a very likely candidate for being cysteine proteinase converting factor. The peptidoglycan was able to induce changes in the types of proteinases expressed in the slime molds within the time expected time period. Secondly, it was able to override the dormancy of the wild type young spores of NC4, and it also affected the germination kinetics of SG1 spores by decreasing the lag period. Similar effects have been noted when whole bacterial cell extracts were used. Further, this work also supports the view that the conformational change is responsible for the activation of cysteine proteinases in slime molds. (Abstract shortened by UMI.)Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1999 .W65. Source: Masters Abstracts International, Volume: 40-03, page: 0640. Adviser: D. A. Cotter. Thesis (M.Sc.)--University of Windsor (Canada), 1999