Amyloidogenic behavior of different intermediate state of stem bromelain: A biophysical insight.
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 to overcome the aggregation related problems of stem bromelain during formulations in pharmaceutical industry.
Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, UP 202002, India.
Masihuz
M
Zaman
Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, UP 202002, India.
Aquib
A
Ehtram
Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, UP 202002, India.
Sumit Kumar
SK
Chaturvedi
Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, UP 202002, India.
Saima
S
Nusrat
Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, UP 202002, India. Electronic address: rizwanhkhan1@gmail.com.
Rizwan Hasan
RH
Khan
D031230:Ananas / Q000201:enzymology*; D001963:Bromelains / Q000737:chemistry*; D002942:Circular Dichroism; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D010940:Plant Proteins / Q000737:chemistry*; D066329:Protein Aggregates; D013056:Spectrophotometry, Ultraviolet
D010940:Plant Proteins; D066329:Protein Aggregates; D001963:Bromelains; C091760:stem bromelain
Aggregation; Amyloid; Induction; Stem bromelain; pH