Immunological detection of cDNA clones encoding the uncoupling protein of brown adipose tissue: evidence for an antigenic determinant within the C-terminal eleven amino acids.

Poly(A)+RNA was isolated from brown adipose tissue of cold acclimated rats and a fraction enriched for uncoupling protein mRNA was used to generate a cDNA library in pBR 322. Immunological screening of 1,500 colonies with an affinity-purified antiserum against the uncoupling protein yielded five positive clones, pUCPrat1-5. Clone pUCPrat2 encoded the C-terminal 54 amino acids of rat uncoupling protein and exhibited 90% amino acid homology with the hamster protein. Clones pUCPrat3-5 encoded only the C-terminal 11 amino acids suggesting that an antigenic determinant lies within this sequence.