Papers by Keyword: Refolding

Abstract: Bio-templates such as proteins, lipids offer rich structural and functional diversity for the synthesis of nanoparticles by controlling their shape, size and orientation. In this work we have exploited a pH dependent folding-refolding feature of Horse Spleen Apoferritin (HsAFr) to synthesize copper and manganese oxide nanoparticles in a controlled manner. Two methods of preparation were used in this study. In the first method, Copper Sulphate (100 mM) and Manganese Chloride (4.8 mM) have been incubated with the protein and the pH dynamically adjusted for homogeneous incorporation of the metal ions into the HsAFr shell. The second study involved the incorporation of Cu²⁺ and Mn²⁺ inside HsAFr cavity and subsequent designing of nanoclusters of the respective oxides. UV, fluorescence and far-UV circular dichroism (far-UV CD) spectroscopic techniques have been used to study the mineralization effect of the metal inside the HsAFr cavity. Size determination carried out using XRD suggested an average size ranging from 20-30 nm. The EPR of the nanoclusters show that incorporation of Mn²⁺ leads to a characteristic magnetoferritin behavior.

Abstract: The objective of this study was to develop an efficient method for the production of bioactive bone morphogenetic protein 2 (BMP-2). A recombinant plasmid encoding mature human BMP-2 was transferred and expressed at a high level in E.coli. Most of the aimed proteins existed in inclusion bodies. The non-active recombinant human BMP-2 (rhBMP-2) monomer in inclusion bodies was refolded and simultaneously purified using hydroxyapatite (HA) chromatography. After oxidization of the monomer, the rhBMP-2 dimmer showed biological activity by the induction of alkaline phosphate activity in C2C12 cells. The refolding yield was about 30% and the purity was about 90% just by one chromatography process.