[Interaction of the glycoprotein from the Bacillus pumilis cell wall with liposomes]

Area of Science:

• Microbiology
• Biochemistry
• Biophysics

Background:

• The cell wall of Bacillus pumilis contains a glycoprotein component (GP-50) with a molecular weight of 50 kDa.
• Liposomes are model systems used to study membrane interactions.

Purpose of the Study:

• To investigate the interaction between Bacillus pumilis cell wall glycoprotein (GP-50) and liposomes derived from bacterial lipids.
• To determine the effect of GP-50 on the barrier properties of these liposomes.

Main Methods:

• Centrifugation
• Gel-filtration chromatography using Sephadex G-50 and G-150

Main Results:

• GP-50 sorbed onto liposomes composed of bacterial lipids.
• This sorption disturbed the liposomes' barrier integrity, leading to the release of a low-molecular-weight label.
• GP-50 had no discernible effect on liposomes prepared from egg lecithin.

Conclusions:

• Electrostatic forces are crucial for the initial interaction between GP-50 and the lipid components of microbial envelopes.
• GP-50's interaction with bacterial liposomes suggests a specific mechanism involving membrane perturbation.