Mixed Bis-Lactams. A Highly Polar Stationary Phase for the Gas Chromatography of Low Molecular Weight Hydrocarbons

1978 ◽  
Vol 16 (2) ◽  
pp. 79-81 ◽  
Author(s):  
M. Ravey
Keyword(s):  
Molecular Weight ◽  
Gas Chromatography ◽  
Stationary Phase ◽  
Low Molecular Weight ◽  
Polar Stationary Phase

A ligand-receptor model for the cohesive behaviour of Dictyostelium discoideum axenic cells

1979 ◽  
Vol 37 (1) ◽  
pp. 157-167
Author(s):  
A.R. Jaffe ◽  
A.P. Swan ◽  
D.R. Garrod
Keyword(s):  
Molecular Weight ◽  
Stationary Phase ◽  
Chelating Agent ◽  
Cell Types ◽  
Low Molecular Weight ◽  
Receptor Model ◽  
Phase Growth ◽  
Developmentally Regulated ◽  
Receptor System ◽  
Contact Sites

Axenically grown cells of D. discoideum Ax-2 harvested in the log phase of growth, cohere rapidly when shaken in phosphate buffer. After 3.5 days in the stationary phase of growth, cells become completely non-cohesive. Although they do not stick to each other, stationary phase cells do stick to both log phase cells and aggregation-competent cells. The cohesion of stationary phase cells with these other 2 cell types is inhibited by both EDTA and the low-molecular-weight factor which we have previously demonstrated in stationary-phase growth medium. There is a decline in the sensitivity of slime mould cell cohesion to the low-molecular-weight inhibitory factor as the cells become aggregation-competent. This effect parallels the developmentally-regulated decline in sensitivity to EDTA. The low-molecular-weight inhibitor is not a chelating agent, however. The effect of the inhibitor seems to be specifically against contact sites-B mediated cohesion. We suggest that the simplest cohesive mechanism which can explain our results, is that the EDTA-sensitive cohesion of log phase cells could be dependent on a ligand-receptor system.

Sign in / Sign up

Export Citation Format

Share Document