Isolation and purification of a Thy-1-like glycoprotein from sheep brain and its distribution in ovine tissues.

Standard methods for the purification of Thy-1 were applied to sheep brain to purify a sheep brain membrane glycoprotein (SBMG). On 12 per cent sodium dodecylsulphate polyacrylamide gels this glycoprotein was shown to be a doublet with apparent molecular weights 24,000 and 25,000. By a number of physicochemical criteria SBMG was shown to have properties similar to those previously reported for Thy-1 isolated from other species. Immunological investigations, however, revealed that SBMG did not react with rabbit anti-rat Thy-1 and rabbit anti-SBMG did not recognise rat or chicken brain. By fluorescent antibody techniques the tissue distribution of SBMG appeared to be similar to that of Thy-1 in other species. A small population of peripheral blood and intestinal lymph lymphocytes were stained with anti-SBMG. These results suggest that sheep have an immunologically distinct Thy-1 homologue.