In the uncoupling protein from brown adipose tissue the C‐terminus protrudes to the c‐side of the membrane as shown by tryptic cleavage

FEBS Letters

Eckerskorn, Christoph¹  Klingenberg, Martin¹ 

[1] Institute for Physical Biochemistry, University of Munich, Goethestrasse 33, 8000 Munich 2, FRG

关键词: Uncoupling protein;    C-terminus;    Trypsin digestion;    UCP;    uncoupling protein;   

DOI  :  10.1016/0014-5793(87)80572-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Limited proteolytic digestion of the uncoupling protein (UCP) with trypsin yielded a cleavage product only about 2 kDa smaller than the original UCP (33 kDa). This cleavage can be obtained with the solubilized isolated protein detergent micelle as well as in original brown adipose mitochondria. The cleavage site is identified by C-terminal sequence to be located near the C-terminus at lysine 292. This C-terminus, a 10 residue long peptide, is strongly hydrophilic and can be expected to be localized outside the membrane. In UCP this C-terminal stretch represents a structural difference to the similarly folded ADP/ATP carrier which does not form a corresponding cleavage product. Comparison of tryptic cleavage of UCP in mitochondria with differently broken outer membrane, in sonic particles of mitochondria, as well as in UCP proteoliposomes, indicate that the C-terminus is directed versus the cytosolic site of the membrane. Because of the easy susceptibility to trypsin, the cleavage site must be surface-exposed and the C-terminal section unusually mobile.

【 授权许可】

Unknown