Adsorption to silica nanoparticles of human carbonic anhydrase II and truncated forms induce a molten‐globule‐like structure

FEBS Letters

Freskgård, Per-Ola²  Elwing, Hans³  Carlsson, Uno²  Billsten, Peter¹  Jonsson, Bengt-Harald⁴ 

[1] IFM-Laboratory of Applied Physics, University of Linköping, S-581 83 Linköping, Sweden;IFM-Department of Chemistry, Linköping University, S-581 83 Linköping, Sweden;Laboratory of Interface Biophysics, Göteborg University, S-413 90 Göteborg, Sweden;Department of Biochemistry, Umeå University, S-90187 Umeå, Sweden

关键词: Human carbonic anhydrase II;    Adsorption;    Molten globule;    Circular dichroism;    Fluorescence;    Nanoparticle;    ANS;    8-anilino-1-naphthalenesulfonic acid;    DNSA;    5-dimethylaminonaphthalene 1-sulfonamide;    HCAIIpwt;    pseudo-wild type of human carbonic anhydrase II with a C206S mutation;    GuHCl;    guanidine hydrochloride;    Trunc 5;    N-terminally truncated at position 5;   

DOI  :  10.1016/S0014-5793(96)01431-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Human carbonic anhydrase II pseudo-wild type (HCAII_pwt) and two truncated variants were adsorbed to ≈9 nm silica nanoparticles. Ellipsometry was used as an indirect measure of protein adsorption. The structural changes of adsorbed proteins were investigated with the use of circular dichroism (CD), intrinsic fluorescence, ANS binding ability and inhibitor binding capacity. It was found that the variants that were truncated at positions 5 and 17 in the N-terminal end attain a molten-globule-like state after interaction with the silica nanoparticles. In contrast, the more stable HCAII_pwt retained most of its native structure after 24 h adsorption to silica nanoparticles. The result suggests that surface induced unfolding may give rise to intermediates similar to those for unfolding induced by, for example GuHCl. Thus, the intermediate observed has some features of the molten globule.

【 授权许可】

Unknown