ABSTRACT
Background: Protein aggregation is one of the important, common and troublingproblems in biotechnology, pharmaceutical industries and amyloid-re-lated disorders
Methods: In the present study, the inhibitory effects of some carbohydrates [alginate,beta -cyclodextrin and trehalose] on the formation of nano-globular aggregates fromnormal [HSA] and glycated [GHSA] human serum albumin were studied; when theformation of aggregates was induced by the simultaneous heating and addition ofdithiotheritol. For the investigations, the biophysical methods of UV-vis spectrophotometry,circular dichroism spectroscopy, transmission electron microscopy andtensiometry were employed
Results: The effect of inhibitory mechanism of these inhibitors on the aggregation ofHSA and GHSA was expressed and compared together
Conclusion: The results showed that the nucleus formation step of the aggregationprocess of HSA and GHSA was different in the presence of alginate [compared tobeta -cyclodextrin and trehalose]. The inhibition efficiencies of the carbohydrates on the aggregateformation of HSA and GHSA were different, arising from the differences inthe hydrophobicities of HSA and GHSA, and also, the differences between HSA-andGHSA-carbohydrate interactions
ABSTRACT
The mature core protein of the Hepatitis C virus [HCVC173] carrying pelB as a signal peptide [PelB::core] was overexpressed in Escherichia coli as 18% and 23.3% of the host's total protein, in flask and fermentor cultivation, respectively. A final specific yield of 25 +/- 1 mg HCVC173/g dry cell weight and an overall productivity of 51 +/- 1 mg HCVC173/l/h were obtained in the stirred-tank fermentor. The recombinant PelB::core protein was overexpressed as the inclusion body [IB] form, higher than the expected level when compared to the HCVC173, which was also showed by the analysis of secondary structure of mRNAs and calculation of the Codon Adaptation Index of the gene. The results showed that the combined effects of protein fusion and the signal sequence significantly enhanced the production of recombinant mature HCVC173 in E. coli. Therefore, the fusion form of the mature HCV core protein and the conditions defined in this study provide an alternative strategy for HCVC173 production in high cell density culture of E. coli