wizyta

od 2020-09-20

Title: Spectroscopic and SAXS studies of human cystatin c mutants - early stages of amyloid formation process

Source: Biophysical Journal

Year : 2015

Abstract:

Human cystatin C (HCC) is a cysteine protease inhibitor. This protein in pathological conditions, forms dimers via a “domain swapping” mechanism. HCC is also associated with two types of amyloid deposition diseases - hereditary amyloid angiopathy (related to the Leu68Gln mutation) and wild-type cystatin C co-precipitation.

The aim of our studies was the characterisation of the self-assembling properties of native and mutated (at positions 57 or 68) forms of human cystatin C in solution. The structure, overall conformation and secondary structure changes in solution were studied by Fourier transformed infrared spectroscopy (FTIR), circular dichroism spectroscopy (CD), dynamic light scattering (DLS) and time resolved small angle scattering of synchrotron radiation (TR-SAXS).

SAXS data for native and mutated HCC were subjected to analysis by using SVD and MCR-ALS methods as well as the low resolution structure determination. Besides the monomeric forms of human cystatin C, also dimers and higher oligomers were formed even after short (50-ms) exposure on synchrotron radiation. In addition we observed for first time, formation of domain swapped dimers of human cystatin C induced by irradiation. The spectroscopic studies confirmed conformational changes.

Authors acknowledge also the partial support by HARMONIA3 grant (Project No. 2012/06/M/ST4/00036) from National Science Centre (Poland).

DOI: 10.1016/j.bpj.2014.11.2827   (Pobrane:  2020-11-05)