Bait region‐thiol ester mapping in human α 2‐macroglobulin

FEBS Letters

Beth, Albert H.³  Hideg, Kálmán⁴  Gettins, Peter G.W.²  Crews, Brenda¹ 

[1] Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA;Department of Biochemistry, M/C 536, University of Illinois-Chicago, 1819-1853 W. Polk Street, Chicago, IL, 60612-4316, USA;Department of Physiology & Molecular Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA;Central Laboratory for Chemistry, University of Pécs, Pécs, Hungary

关键词: α 2-Macroglobulin;    Human;    Spin label;    Nitroxide;    Paramagnetic mapping;    Bait region;    Thiol ester;    NMR (1H);    α 2M;    α 2-macroglobulin;    H0559;    3-(α-bromoacetyl)-2;    2;    5;    5-tetramethyl-2;    5-dihydropyrrol-1-yloxyl;    PROXYL;    2;    2;    5;    5tetramethylpyrrolidine-l-oxyl;    TEMPO;    2;    2;    6;    6-tetramethylpiperidine1-oxyl;   

DOI  :  10.1016/0014-5793(95)00530-M

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The separations between aromatic residues in the bait region and nitroxide spin labels attached to the thiol ester-forming residues (Cys⁹⁴⁹ and Gln⁹⁵²) in human α ₂-macroglobulin (α ₂M) have been determined from paramagnetic broadening effects of the spin labels on bait region ¹H NMR signals. We found that both the Cys⁹⁴⁹ and Gln⁹⁵² residues are within 11–17 Å of the aromatic residues in the bait region, with closer approach of some residues to the Gln⁹⁵² spin label than to the spin label attached to Cys⁹⁴⁹. A model of the location of bait regions and thiol esters within an α ₂M half-molecule is proposed that places the bait regions in the central region of α ₂M at the interface between the subunits.

【 授权许可】

Unknown