Probing the conformational changes and peroxidase-like activity of cytochrome c upon interaction with iron nanoparticles

Herein, the interaction of iron nanoparticle (Fe-NP) with cytochrome c (Cyt c) was investigated, and a range of techniques such as dynamic light scattering (DLS), zeta potential measurements, static and synchronous fluorescence spectroscopy, near and far circular dichroism (CD) spectroscopy, and ultraviolet–visible (UV–vis) spectroscopy were used to analyze the interaction between Cyt c and Fe-NP. DLS and zeta potential measurements showed that the values of hydrodynamic radius and charge distribution of Fe-NP are 83.95 ± 3.7 nm and 4.5 ± .8 mV, respectively. The fluorescence spectroscopy results demonstrated that the binding of Fe-NP with Cyt c is mediated by hydrogen bonds and van der Waals interactions. Also Fe-NP induced conformational changes in Cyt c and reduced the melting temperature value of Cyt c from 79.18 to 71.33°C. CD experiments of interaction between Fe-NP and Cyt c revealed that the secondary structure of Cyt c with the dominant α-helix structures remained unchanged whereas the tertiary structure and heme position of Cyt c are subjected to remarkable changes. Absorption spectroscopy at 695 nm revealed that Fe-NP considerably disrupt the Fe…S(Met80) bond. In addition, the UV–vis experiment showed the peroxidase-like activity of Cyt c upon interaction with Fe-NP. Hence, the data indicate the Fe-NP results in unfolding of Cyt c and subsequent peroxidase-like activity of denatured species. It was concluded that a comprehensive study of the interaction of Fe-NP with biological system is a crucial step for their potential application as intracellular delivery carriers and medicinal agents.     

Molecular assessment of proteins encoded by the mitochondrial genome of Clarias batrachus and Clarias gariepinus

The population of catfish, Clarias batrachus has substantially diminished in various countries and studies show that another related species Clarias gariepinus is replacing it. The better adaptability and survivability of C. gariepinus over C. batrachus could be attributed to the metabolic differences between these two species, which is primarily regulated by mitochondrial activities. To understand the reasons behind this phenomenon, we performed in silico analyses to decipher the differences between the proteins encoded by the mitochondrial genome of these two related species. Our analysis revealed that out of thirteen, twelve proteins encoded by the mitochondrial genome of these two species have substantial variations between them. We characterised these variations by analysing their effect on secondary structure, intrinsic disorder predisposition, and functional impact on protein and stability parameters. Our data show that most of the parameters are changing between these two closely related species. Altogether, we demonstrate the molecular insights into the mitochondrial genome-encoded proteins of these two species and predict their effect on protein function and stability that might be helping C. gariepinus to gain survivability better than the C. batrachus.     

Stable synthesis of viral protein 2 of infectious bursal disease virus in Saccharomyces cerevisiae.

Viral protein 2 (VP2) from infectious bursal disease virus and its precursor polyprotein (N-VP2-VP4-VP3-C), in the absence of their native N-terminal region (19 amino acids), required fusion of yeast presequences for their stable synthesis in Saccharomyces cerevisiae [Jagadish et al., Gene 95 (1990) 179-186]. Restoration of the missing 19 aa resulted in stable synthesis of VP2, indicating the significance of the N-terminal region in protein stability.     

Aryltellurium(IV) trichlorides, aryl(trans-2-chloro-1-cycloalkyl)tellurium(IV) dichlorides, and aryl(trans-2-ethoxy-1-cycloalkyl)tellurium(IV) dichlorides

Aryltellurium(IV) trichlorides react with parent arenes to give diaryltellurium(IV) dichlorides and with cycloalkenes to give aryl(trans-2-chloro-1-cycloalkyl)tellurium(IV) dichlorides or aryl(trans-2-ethoxy-1- cycloalkyl)tellurium(IV) dichlorides in the presence of ethanol.