Chemical properties of the placental FC gamma receptor.

The carbohydrate and amino acid compositions of the purified Fc receptor from human placental trophoblasts are described. The placental receptor is a glycoprotein. The total content of carbohydrates in the receptor is 30% (w/w). The major carbohydrate components are galactose, N-acetylglucosamine, fucose, and mannose. The placental receptor has a high content of acidic amino acids and a relatively low number of aromatic and hydrophobic amino acid residues. The ratio of contents of hydrophilic to hydrophobic amino acids is 2:1. The hydrophilic nature of the receptor molecules is shown by charge-shift electrophoresis.