Influence of charge and molecular size on membrane stabilization

Area of Science:

• Biochemistry
• Membrane Biophysics
• Pharmacology

Background:

• Chlorpromazine's antihemolytic effect was previously linked to interactions with membrane sialic acids.
• This suggested a role for charge interactions in membrane stabilization.

Purpose of the Study:

• To investigate the antihemolytic action of simpler molecules with varying charges.
• To determine the primary factors (lipophilicity, charge, polarity) influencing membrane stabilization.

Main Methods:

• Enzymic removal of sialopeptides from red cell membranes.
• Testing the antihemolytic effects of various aliphatic monoamines, diamines, and charged molecules.
• Comparing the potency of positively and negatively charged compounds.

Main Results:

• Sialopeptide removal did not affect the membrane stabilizing actions of simple aliphatic amines.
• Positively charged molecules were more potent antihemolytic agents than negatively charged ones.
• Membrane stabilizing activity correlated primarily with lipophilicity and secondarily with polarity.

Conclusions:

• Membrane stabilization by simple molecules is primarily determined by lipophilicity and polarity.
• Interactions with enzymically accessible sialopeptides on the cell surface are not essential for this activity.
• Charge plays a role, with positive charges being more effective than negative charges.