Title
Aloe emodin, an anthroquinone from Aloe vera acts as an anti aggregatory agent to the thermally aggregated hemoglobin
Author
Mohammad Furkan, Md Tauqir Alam, Asim Rizvi, Kashan Khan, Abad Ali, Shamsuzzaman, Aabgeena Naeem
Year
2017
Journal
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
Abstract
Aggregation of proteins is a physiological process which contributes to the pathophysiology of several maladies including diabetes mellitus, Huntington's and Alzheimer's disease. In this study we have reported that aloe emodin (AE), an anthroquinone, which is one of the active components of the Aloe vera plant, acts an inhibitor of hemoglobin (Hb) aggregation. Hb was thermally aggregated at 60 °C for four days as evident by increased thioflavin T and ANS fluorescence, shifted congo red absorbance, appearance of β sheet structure, increase in turbidity and presence of oligomeric aggregates. Increasing concentration of AE partially reverses the aggregation of the model heme protein (hemoglobin). The maximum effect of AE was observed at 100 μM followed by saturation at 125 μM. The results were confirmed by UV–visible spectrometry, intrinsic fluorescence, ThT, ANS, congo red assay as well as transmission electron microscopy (TEM). These results were also supported by Fourier transform infrared spectroscopy (FTIR) and circular dichroism (CD) which shows the disappearance of β sheet structure and appearance of α helices. This study will serve as baseline for translatory research and the development of AE based therapeutics for diseases attributed to protein aggregation.
Instrument
J-815
Keywords
Circular dichroism, Secondary structure, Thermal stability, Aggregation, Biochemistry