I noticed that a lot of transformation protocols for gram positive bacteria (especially lactic acid bacteria) call for high concentrations of glycine and/or threonine as a "cell wall weakening agent" to let foreign DNA into the cytoplasm more easily. I haven't been able to find a publication yet that specifies exactly how they weaken cell walls. Does anyone know the mechanism behind it?
These agents are used because of the thick cell wall of gram positives. Other agents in this category are lysozymes and pencillin G. Glycine works by replacing the D- and L- alanine residues of the peptidoglycan network, thus providing a weakened cell wall that allow the incorporation of foreign DNA while retaining the viability of the organism. (For more information, check out this: Hammes W, Schleife K, Kandler O. Mode of action of glycine on biosynthesis of peptidoglycan. J Bacteriol. 1973;116:1029–1053)
- Badges
- Science topic