Glycation induced conformational transitions in cystatin proceed to form biotoxic aggregates: A multidimensional analysis

Publication date: September 2018Source: Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics, Volume 1866, Issue 9Author(s): Sheraz Ahmad Bhat, Waseem Feeroze Bhat, Hussain Arif, Mohammad Afsar, Aamir Sohail, Md. Shahnawaz Khan, Md. Tabish Rehman, Rais Ahmad Khan, Bilqees BanoAbstractHyperglycaemic conditions facilitate the glycation of serum proteins which may have predisposition to aggregation and thus lead to complications. The current study investigates the glycation induced structural and functional modifications of chickpea cystatin (CPC) as well as biological toxicity of the modified protein forms, using CPC-glucose as a model system. Several structural intermediates were formed during the incubation of CPC with glucose (day 4, 8, 12, & 16) as revealed by circular dichroism (CD), altered intrinsic fluorescence, and high ANS binding. Further incubation of CPC with glucose (day 21) formed abundant β structures as revealed by Fourier transform infrared spectroscopy and CD analysis which may be due to the aggregation of protein. High thioflavin T fluorescence intensity and increased Congo red absorbance together with enhanced turbidity and Rayleigh scattering by this modified form confirmed the aggregation. Electron microscopy finally provided the valid physical authentication about the presence of aggregate structures. Functional inactivation of glucose incubated CPC was also observed with time. Single cell electrophoresis of lymphocytes and plasmid nicking assa...
Source: Biochimica et Biophysica Acta (BBA) Proteins and Proteomics - Category: Biochemistry Source Type: research