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Interaction of bilirubin with human erythrocyte membranes. Bilirubin binding to neuraminidase- and phospholipase-treated membranes.

ABSTRACT: Saturable bilirubin binding to human erythrocyte membranes was measured before and after digestion with neuraminidase and phospholipases. Neuraminidase-treated erythrocyte membranes did not show any change in their binding properties, indicating that gangliosides could be excluded as candidates for saturable bilirubin-binding sites on erythrocyte membranes. Although bilirubin-binding properties of the membranes did not change after phospholipase D digestion, either, phospholipase C treatment greatly enhanced bilirubin binding. Thus it is suggested that a negatively charged phosphoric acid moiety of phospholipids on the membrane surface may play a role to prevent a large amount of bilirubin from binding to the membranes. Further saturable bilirubin binding to inside-out sealed erythrocyte membrane vesicles showed values comparable with those of the right-side-out sealed membranes, suggesting that the bilirubin-binding sites may be distributed on both outer and inner surfaces of the membranes, or may exist in the membranes where bilirubin may be accessible from either side.

SUBMITTER: Sato H

PROVIDER: S-EPMC1148495 | biostudies-other | 1987 Nov

REPOSITORIES: biostudies-other

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Interaction of bilirubin with human erythrocyte membranes.

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