T-cell antigen receptor is a heterodimer of disulfide-linked α- and β-chains. Although the essential features of T-cell receptor seem to be rather similar to those of immunoglobulin, the amount of T-cell receptor expressed on the surface of a T-cell is not large enough to be analyzed physico-chemically. In this study, the DNA fragment encoding 120 amino acids from the 116th to the 235th of the murine, β-chain which corresponds to the presumed constant domain was inserted into an expression vector in E. coli. A large amount of this 18 kDa protein was observed to be synthesized in E. coli, and might be a good source for the three dimensional analysis of the T-cell receptor molecule.
