Amino acids and short peptides do not always stabilize globular proteins: A differential scanning calorimetric study on their interactions with bovine alpha-lactalbumin

Amino acids and related compounds have been shown to confer stabilization to proteins; however, the generalization of such a statement is far from reality as there is a lack of experimental data on the interactions of amino acids and short peptides with different proteins. In particular, there are only a few reports(1-3) on direct differential calorimetric studies on these systems. Using DSC, we have studied the thermal denaturation of bovine alpha-lactalbumin in the presence-of-glycine, alanine, leucine, lysine, aspartic acid, glutamic acid, diglycine, triglycine, tetraglycine, pentaglycine, glycyl-leucine and glycyl-glycyl-leucine at neutral pH. It has been observed that these amino acids and peptides either do not provide thermal stabilization to a-lactalbumin or that the extent of stabilization is negligibly small. However, sucrose was able to confer thermal stability at neutral pH. All the thermal denaturations were-found to be two-state (i.e. natured reversible arrow denatured) and reversible and provide quantitative thermodynamic parameters associated with them. The results have been interpreted in terms of a fine balance between the preferential exclusion and binding which takes place during the course of the denaturation reaction. It follows from this study that the amino acids and peptides do not always stabilize globular proteins

Thermal unfolding of hen egg-white lysozyme in the presence of 4-chlorobutan-1-ol

High sensitivity differential scanning calorimetry transitions for the highly irreversible thermal denaturation of hen egg white lysozyme in the presence of low concentration (> k(2), thus the data fitting to the extreme case of this model ie. N --> F where N is the native state, D is the unfolded one and F is the final irreversibly arrived state. However, the thermal denaturation in the presence of 3-chloro-propan- 1-ol, 3-chloropropan-1,2-diol and their corresponding normal alcohols was earlier(ref 1) observed to be reversible two-state

Studies on the Rhizome Oils from Four Hedychium Species of South India: A Chemotaxonomic Approach

Volume: 59Start Page: 57End Page: 6

Mechanical superiority of Pseudoxytenanthera bamboo for sustainable engineering solutions

Abstract The advancement in natural fibre composites has replaced synthetic fibres in various commercial sectors. Bamboo species possess high mechanical properties due to their lignocellulosic fibre content, which makes them suitable for engineering applications and potential alternatives to solid wood. However, despite Bamboo being composed of 130 genera and 1700 different species, out of which many still remains underexplored. In this study, we investigated the, Lignocellulosic profiling, fibre strength, and mechanical characterization of two species of Pseudoxytenanthera Bamboo: Pseudoxytenanthera ritchiei, Pseudopxytenanthera stocksii, and the results obtained were compared with Bambusa balcooa, one of the priority species of bamboo identified by The International Plant Genetic Resources Institute (IPGRI). BET (Brunauer–Emmett–Teller) was used to quantify the samples’ density, while SEM–EDX and FTIR spectroscopy were used for elemental analysis. The samples were then subjected to tensile test in addition, thermogravimetric analysis and water absorption test were carried out for the three species. The results showed that Pseudoxytenanthera species possessed superior chemical and mechanical characteristics compared to the priority species of bamboo used for composites. Out of the two Pseudoxytenanthera species studied, Pseudoxytenanthera stocksii exhibited the highest values of cellulose, hemicellulose, lignin, pectin, ash, carbon, and silicon, indicating its chemical superiority. Moreover, Pseudoxytenanthera stocksii also showed higher mechanical values for tensile strength, making it suitable for a variety of engineering applications. The TGA values also indicated that Pseudoxytenanthera stocksii is stable at high temperatures when compared with other natural fibres