The amino acid sequence , disulphide bonds and an unusual hydrophobic region
The full sequence of the Thy-1 membrane glycoprotein Thy-1 membrane glycoprotein of rat brain is reported
The sequence was determined from tryptic and V-8 proteinase peptides and consisted of 111 amino acids
The amino terminus was blocked and consisted of a pyroglutamic acid residue
The molecule contained two disulphide bonds, namely Cys-9--Cys-111 and Cys-19--Cys-85
Three N-linked amino sugars were located at Asn-23, Asn-74 and Asn-98
In each case the sequence on the C-terminal side of the attachment point was Asn-Xaa- Thr as would be expected for N-linkage
The C-terminal peptides were unusual, in that they were either obtained in a highly aggregated form, or could only be purified after binding to Brij 96 micelles
Thus they appeared to have hydrophobic properties, yet did not contain any extended sequence of hydrophobic amino acids
Other unusual features of the C-terminal peptides were the presence of unidentified ninhydrin-positive material and of glucosamine and galactosamine.
The C-terminal residue has not been directly identified but Cys-111 is the last conventional amino acid
It is suggested that the hydrophobic properties of the C-terminal peptides may be due to the linkage of lipid
The sequence of the Thy-1 glycoprotein showed homologies with immunoglobulin domains
This relationship is examined in detail in the paper following [Cohen et al. (1981) Biochem