Demonstration of a tandem pair of complement protein modules in GABAB receptor 1a

FEBS Letters

Barlow, Paul N.¹  Xiao, Yuanyuan³  Hawrot, Edward³  Shi, Qing-luo³  Kirkitadze, Marina¹  Norman, David² 

[1] The Edinburgh Centre for Protein Technology, Joseph Black Building, King's Buildings, Edinburgh EH9 3JJ, UK;Department of Biochemistry, Medical Sciences Institute, Dundee University, Dundee DD1 4HN, UK;Department of Molecular Pharmacology, Physiology and Biotechnology, Brown University, Box G-B403, Providence, RI 02192, USA

关键词: SCR;    Sushi;    GABAB receptor;    Epilepsy;    Drug target;   

DOI  :  10.1016/S0014-5793(98)00794-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We have subcloned and expressed the N-terminal portion of the recently sequenced metabotropic GABA receptor, GABA_BR1a. This region of the receptor contains a complement protein-like amino acid sequence. The purified 140-residue recombinant protein fragment was soluble and stable. Mass spectrometry indicated formation of four disulfide bonds, as expected if two complement protein modules (CPs, also known as SCRs, Sushi domains) are formed. The circular dichroism spectrum was unusual and characteristic of CPs. Differential scanning calorimetry demonstrated a melting point (64°C), and total enthalpy commensurate with two fully folded domains. We thus conclude that the 1a subtype of the GABA_B receptor, but not the 1b subtype, contains a pair of CPs and we present a three-dimensional model of this region.

【 授权许可】

Unknown