Amyloidogenic behavior of different intermediate state of stem bromelain; A Biophysical Insight

Published Date
Available online 31 May 2016, doi:10.1016/j.ijbiomac.2016.05.107

In Press, Accepted Manuscript — Note to users

Title 

Amyloidogenic behavior of different intermediate state of stem bromelain; A Biophysical Insight

• Author 

• Masihuz Zaman
• Aquib Ehtram
• Sumit Kumar Chaturvedi
• Saima Nusrat
• Rizwan Hasan Khan ^,,

• Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, UP 202002, India

Received 22 February 2016. Revised 20 April 2016. Accepted 30 May 2016. Available online 31 May 2016.

Abstract

Stem bromelain, a cysteine proteases from Ananas comosus is a widely accepted therapeutic drug with broad medicinal application. It exists as intermediate states at pH 2.0 and 10.0, where it encountered in gastrointestinal tract during adsorption (acidic pH) and in gut epithelium (alkaline pH), respectively. In this study, we monitored the thermal aggregation/amyloid formation of SB at different pH intermediate states. Thermal treatment of stem bromelain at pH 10.0 favors the fibrillation in which the extent of aggregation increases with increase in protein concentration. However, no fibril formation in stem bromelain at pH 2.0 was found at all the concentration used at pH 10.0. The fibril formation was confirmed by various techniques such as turbidity measurements, Rayleigh light scattering, dye binding assays and far UV circular dichroism. The Dynamic light scattering confirmed the formation of aggregates by measuring the hydrodynamic radii pattern. Moreover, microscopic techniques were performed to analyze the morphology of fibrils. The aggregation behavior may be due to variation in number of charged amino acid residues. The less negative charge developed at pH 10.0 may be responsible for aggregation. This work helps in to overcome the aggregation related problems of stem bromelain during formulations in pharmaceutical industry.

Graphical abstract

Keywords

• Aggregation
• Amyloid
• Induction
• pH
• Stem Bromelain

Fig. 1.

Fig. 2.

 Table 1

Table 1.

Fig. 3.

Fig. 4.

 Table 2

Table 2.

Fig. 5.

Fig. 6.

 Table 3

Table 3.

Fig. 7.

• ⁎ 
  Corresponding author.

© 2016 Elsevier B.V. All rights reserved.

Note to users: Accepted manuscripts are Articles in Press that have been peer reviewed and accepted for publication by the Editorial Board of this journal. They have not yet been copy edited and/or formatted in the journal house style, and may not yet have the full ScienceDirect functionality, e.g., supplementary files may still need to be added, links to references may not resolve yet etc. The text could still change before final publication.

Although accepted manuscripts do not have all bibliographic details available yet, they can already be cited using the year of online publication and the DOI, as follows: author(s), article title, journal (year), DOI. Please consult the journal's reference style for the exact appearance of these elements, abbreviation of journal names and use of punctuation.

When the final article is assigned to an issue of the journal, the Article in Press version will be removed and the final version will appear in the associated published issue of the journal. The date the article was first made available online will be carried over.

For further details log on website :

http://www.sciencedirect.com/science/journal/aip/01418130