Effect of polychlorinated biphenyls (PCBs) on phospholipid membrane fluidity

Abstract
Polychlorinated biphenyls (PCB) are highly lipophilic molecules widely distributed throughout the environment. They accumulate in adipose tissue and remain as a source of continuing exposure to the rest of the body. Interaction of PCB with phospholipid bilayer membranes was monitored by spin label technique. Under indentical experimental conditions, increased Cl substitution in the 2,2'',6,6'',-positions of biphenyl rings enhanced motion of spin label in bilayer membrane. Perturbation which increased membrane fluidity could be correlated to degree of non-coplanarity of biphenyl rings incorporated into bilayer membranes.