The conversion of a protein from its native conformation to the pathogenic form is a critical event in the pathogenesis of several neurodegenerative disorders such as Alzheimer’ s (AD), Parkinson’ s, and Huntington’ s diseases, along with type II diabetic mellitus. Although there are several reports on the mechanism of protein aggregation, the actual conformation playing a part in the pathogenicity is yet unclear. Accordingly, the present study summarizes the early pathogenic conformation resulting in several protein aggregations. It is well-documented that a pre-MOLTEN GLOBULE (MG) structure appears at the early stages of some proteins. Pre-MG is one of the intermediate structures, which is formed during some protein unfolding processes. In addition, it is shown that the pre-MOLTEN structure is more flexible than the mature MG one and thus, protein easily rearranges to form amyloid fibrils in this conformation. Therefore, protein aggregation is halted by preventing the pre-MG structure. The strategy of protein aggregation prevention has profound implications in fighting the devastating disorder.

Cytochrome-c (cyt-c) is an electron transport protein, and it is present throughout the evolution. More than 280 sequences have been reported in the protein sequence database (www.uniprot.org). Though sequentially diverse, cyt-c has essentially retained its tertiary structure or fold. Thus a vast data set of varied sequences with retention of similar structure and function makes it a primary candidate for studying molecular evolution, phylogenetics and sequence conservation. When amino acid sequences of mammalian cyts-c are aligned with the sequence of the yeast iso-1-cyt-c (y-cyt-c), it is observed that the yeast protein not only contains five extra N-terminal residues but it has only 60% sequence homology, e.g., with the horse heart cyt-c. Structural and thermodynamic studies suggest that there are four states in the folding equation of y-cyt-c, i.e., Denatured (D) state«Pre MOLTEN GLOBULE (PMG) state«MOLTEN GLOBULE (MG) state«N (Native) state. This review summarises findings of structural and thermodynamic characteristics of these thermodynamic states of y-cyt-c and its folding mechanism.

The anionic surfactant sodium n-dodecyl sulfate (SDS) plays a variety of roles with regard to protein conformation, depending on its concentration. SDS at low concentrations mostly induces the compaction of protein (folding). Examples of this include: the MOLTEN GLOBULE state of acid-unfolded cytochrome c, associated with enhancement of the exothermic enthalpy values of isothermal titration calorimetry and a reversible profile by differential scanning calorimetry; the enzyme activation and compaction of Aspergillus niger catalase, and relationship of calorimetric enthalpy (D Hcal) to van’t Hoff enthalpy (D HVH), which proves the existence of intermolecular and intramolecular interaction during enzyme activation by SDS; the production of a new energetic domain for human apotransferrin and folded state for histone H1 by SDS. SDS at moderate concentrations below the critical micelle concentration (cmc) is a potent denaturant for protein in solution. Protein denaturation is a key method in thermodynamics and binding site analysis and can be used to enhance our understanding of the protein structure-function relationship. The interaction between protein and surfactant, such as SDS, at the cmc level is a complicated interaction, thermodynamically, that should bring about enthalpy correction through micellar dissociation and micelle dilution.

Gold nanoparticles are promising materials for biomedical applications because of the attractive optical properties such as the absorption and scattering of light at resonant wavelength. Due to the fruitful applications of gold nanoparticles (GNPs), they are appropriate for a variety of biological studies. One of the most important applications of nanoparticles is protein carriers, in which transport of therapeutically relevant protein is done to in vivo or in vitro targets. Protein folding and properties of probable intermediates during the folding of proteins had been investigated in several studies. The MOLTEN GLOBULE state, a main intermediate of protein folding, has native-like secondary but perturbation of tertiary structure. Consequently, the influence of gold nanoparticles concentration on a model protein was studied by far-and near-UV circular dichroism (CD), Fourier transform infrared spectroscopy (FTIR), UV-Vis spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM), intrinsic fluorescence emission spectroscopy and 8-Anilino-1naphthalenesulfonic acid binding. The results indicated that the interactions between gold nanoparticles and lysozyme lead to the formation of MOLTEN GLOBULE-like state.

The effects of gating system and pattern geometry on the metal flow in the lost foam casting (LFC) process have been investigated using glass covered mold and video recording system. Unlike convectional casting process, the type of the gating system showed little effect on fillability in lost foam, but pattern thickness had large effect on mold filling. The mold filling behavior seems to be controlled by the combined influences of heat and mass transfer. The flow rate increased with increasing pattern thickness.

In this research, a 3-D mathematical model is developed for simulating electromagnetic continuous removal of inclusions from MOLTEN metals. The model includes the computation of electromagnetic force field and fluid flow in the presence. Of electromagnetic forces. The results of flow field together with electromagnetic force field were further used for calculating the trajectory of inclusions in the MOLTEN metal. Parametric studies were performed to evaluate the effects of various parameters such as magnetic field intensity, inclusion size, and fluid velocity on inclusion removal efficiency in MOLTEN magnesium. In order to verify the mathematical model and visualize the trajectories of particles in the melt flow under electromagnetic force, a physical model was constructed. The predicted particle trajectories and separation in the physical model were compared with those obtained from experiments, which showed a relatively good agreement.