Gas vesicles isolated from Halobacterium cells by lysis in hypotonic solution are structurally weakened.
Analysis of pressure-collapse curves of Halobacterium cells containing gas vesicles and of gas vesicles released from such cells by hypotonic lysis shows that the isolated gas vesicles are considerably weaker than those present within the cells: their mean critical collapse pressure was around 0.049-0.058 MPa, as compared to 0.082-0.095 MPa for intact cells. The hypotonic lysis procedure, which is widely used for the isolation of gas vesicles from members of the Halobacteriaceae, thus damages the mechanical properties of the vesicles. The phenomenon can possibly be attributed to the loss of one or more structural gas vesicle proteins such as GvpC, the protein that strengthens the vesicles built of GvpA subunits: Halobacterium GvpC is a highly acidic, typically "halophilic" protein, expected to denature in the absence of molar concentrations of salt.
Oren
Aharon
A
The Institute of Life Sciences and the Moshe Shilo Minerva Center for Marine Biogeochemistry, The Hebrew University of Jerusalem, Israel. orena@shum.cc.huji.ac.il
Pri-El
Nuphar
N
Shapiro
Orr
O
Siboni
Nachshon
N
D001426:Bacterial Proteins / Q000502:physiology; D001433:Bacteriolysis; D022162:Cytoplasmic Vesicles; D006217:Halobacterium / Q000166:cytology* / Q000502:physiology* / Q000648:ultrastructure; D006874:Hydrostatic Pressure; D007038:Hypotonic Solutions; D008565:Membrane Proteins; D009997:Osmotic Pressure; D011489:Protein Denaturation; D011506:Proteins / Q000502:physiology
D001426:Bacterial Proteins; D007038:Hypotonic Solutions; D008565:Membrane Proteins; D011506:Proteins; C038524:gas vesicle protein