Isolation of the GDP binding protein from brown adipose tissue mitochondria of several animals and amino acid composition study in rat

The nucleotide binding protein (uncoupling protein, GDP binding protein) of brown adipose tissue mitochondria has been isolated from cold adapted rat, newborn guinea pig and newborn rabbit. The purification, using hydroxyapatite in sucrose gradient centrifugation, follows the procedures established previously for the isolation of this protein from cold adapted hamster. A similar degree of purification was obtained, reaching 60 μmol GDP bound/g protein. In SDS gel electrophoresis the purified protein gave a single band of M_r 32 000 from all species.