Loss of calcium sensitivity of plasma gelsolin is associated with the presence of calcium ions during preparation

FEBS Letters

Pope, B.²  Weeds, A.G.²  Hinssen, H.¹  Gooch, J.² 

[1] Developmental Biology Unit, University of Bielefeld. D4800 Bielefeld, FRG;MRC Laboratory of Molecular Biology, Hills Road, Cambridge, England CB2 2QH

关键词: Gelsolin;    Actin binding protein;    Actin filament severing;    Calcium sensitivity;    Fxgelsolin;    human plasma gelsolin expressed in E. coli using the pLeIIFX expression vector [19];    which directs synthesis of a hybrid protein containing the first 31-amino terminal residues of lambda cII protein;    a Factor Xa recognition sequence (FX) as well as gelsolin. PI-actin;    actin reacted on Cys 374 with N-(1-pyrenyl)iodoacetamide;    NBD-actin;    actin reacted with N-ethylmaleimide on Cys 374 then on Lys 373 with 7-chloro-4-nitrobenzeno-2-oxa-1;    3-diazole;   

DOI  :  10.1016/0014-5793(89)81524-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Gelsolin is a calcium-dependent actin severing and capping protein. Calcium ‘opens’ the molecule to make actin binding sites accessible, but removal of calcium from the medium does not necessarily fully reverse this process. The calcium sensitivity of actin monomer binding and actin filament severing is here shown to vary considerably with the source of gelsolin and conditions of preparation. Plasma gelsolin undergoes irreversible loss of calcium sensitivity when prepared in the presence of calcium ions. This is not due solely to effects of bound calcium, because purified human plasma gelsolin expressed in E. coli and stored in calcium shows no comparable loss of calcium sensitivity when prepared or stored in calcium. These results suggest the presence of factors in plasma which, in the presence of calcium, promote an irreversible structural change in gelsolin resulting in permanent loss of calcium sensitivity.

【 授权许可】

Unknown