N-linked glycosylation of the C5a receptor.

The recent cloning of the cDNA encoding the human C5a receptor reveals a single potential site for N-linked glycosylation. Previous studies have suggested the presence of at least one carbohydrate moiety in the C5a receptor. Enzymatic digestion with Endoglycosidase F confirmed this presence and a point mutation at the predicted site of glycosylation was sufficient to lower the apparent molecular weight of the receptor as determined by SDS-PAGE. Removal of the carbohydrate moiety failed to abolish expression of the receptor and brought about only a slight reduction in the dissociation constant of the C5a receptor suggesting that the role of glycosylation in the binding of C5a by its receptor is limited.