the mature human protein appears to be divided into three domains : a hydrophilic 185 amino acid external domain bearing only limited homology to the t-cell surface protein t4 and the immunoglobulin kappa light chain variable region , a 25 amino acid hydrophobic transmembrane segment , and a 126 amino acid cytoplasmic domain rich in prolines and basic residues .
C0877857
immunoglobulin
C0021036
kappa light chain