Bacteria membrane integration models

Fig. 3 Schematic model of light-harvesting compartments in photosynthetic organisms and their position with respect to the membrane and the reaction centers. RC1(2) Photosystem I(II) reaction centre. Peripheral membrane antennas Chlorosome/FMO in green sulfur and nonsulfur bacteria, phycobilisome (PBS) in cyanobacteria and rhodophytes and peridinin-chlorophyll proteins (PCP) in dyno-phytes. Integral membrane accessory antennas LH2 in purple bacteria, LHC family in all eukaryotes. Integral membrane core antennas B808-867 complex in green nonsulfur bacteria, LH1 in purple bacteria, CP43/CP47 (not shown) in cyanobacteria and all eukaryotes.

As discussed above, cationic peptides can form channels in model bilayers. Thus, it seems likely that their primary amibacterial action is to disrupt the integrity of bacterial cytoplasmic membranes. This would have the effect of permitting leakage of ions arxl small metabolites, and destroying the ability of bacteria to maintain a transmembrane proton gradient (proton-motive force) with consequent loss of ability to generate adenosine triphosphate and transport substrates (see Ref. 119 for review of cytoplasmic membranes). 

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