The search for the mechanism of ribosomal peptide bond formation is still ongoing. Even though the actual mechanism of peptide bod formation is still unknown, the dominance of proton transfer in this ...reaction is known for certain. Therefore, it is vital to take the quantum mechanical effects on proton transfer reaction into consideration; the effects of which were neglected in all previous studies. In this study, we have taken such effects into consideration using a semi-classical approach to the overall reaction mechanism. The M06-2X density functional with the 6-31++G(d,p) basis set was used to calculate the energies of the critical points on the potential energy surface of the reaction mechanism, which are then used in transition state theory to calculate the classical reaction rate. The tunnelling contribution is then added to the classical part by calculating the transmission permeability and tunnelling constant of the reaction barrier, using the numerical integration over the Boltzmann distribution for the symmetrical Eckart potential. The results of this study, which accounts for quantum effects, indicates that the A2451 ribosomal residue induces proton tunnelling in a stepwise peptide bond formation.
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•Reaction rate of boronic acid with diols is calculated with five different R-groups.•To account for proton tunnelling quantum corrections are added to the reaction rate.•Higher ...electronegativity results in shortening the proton donor-acceptor distance.•This induces proton tunnelling and increases the reaction rate.
Designing an efficient saccharide sensor in aqueous solution is an ongoing endeavour. Even though using hydrogen bonding groups on the sensor sounds like an efficient way for targeting the saccharides, it might lack accuracy due to the possibility of interaction with the solvent molecules. Boronic acid based sensors on the other hand, covalently and reversibly bind to saccharides with high sensitivity in aqueous medium. Many attempts are done to understand the mechanism of boronic acid’s reaction with diols. However, the binding affinity of fructose cannot be clearly identified in such attempts. This study employs a novel computational approach to increase both reactivity and selectivity of boronic acid towards diols. Using DFT, five different electronegative R-groups are simulated to calculate boronic acid’s reactivity towards diol by adding the tunnelling effect to the calculations, where higher electronegative R-groups reduce the proton donor-acceptor distance that induces proton tunnelling and increases the reaction rate.
Purpose This conceptual paper aims to delineate a comprehensive blueprint for the integration of environmental, social and governance (ESG) principles within the framework of Takaful operations, ...guided by the principles of Maqasid al-Shariah. The primary purpose is to establish a robust foundation for the sustainable transformation of Takaful, aligning it with ethical finance and Islamic values. Design/methodology/approach Using a theoretical research approach, this study delves into the multifaceted dimensions of ESG principles and the principles of Maqasid al-Shariah within the context of Takaful operations. The 17 SDGs/ESG principles and Maqasid al-Shariah are integrated to give a thorough framework for comprehending the disclosure index from western and Islamic ethical viewpoints. The research critically analyses current literature, scholarly works and authoritative sources, drawing inspiration from established approaches. Qualitative content analysis examines and compiles pertinent ideas, and the expert validates the disclosure index. It identifies key convergence, compatibility and divergence points between ESG principles and Maqasid al-Shariah to construct a comprehensive framework for Maqasid-driven ESG integration in Takaful. Findings The paper presents a well-defined blueprint for Maqasid-driven ESG integration in Takaful, revealing substantial areas of alignment between the two frameworks. This alignment is particularly pronounced in protecting life, religion, intellect, lineage and wealth. The blueprint underscores the potential of harmonising ESG principles with the principles of Maqasid al-Shariah, providing Takaful operators with a roadmap for enhancing their ethical credibility, societal impact and environmental stewardship. Research limitations/implications The blueprint outlined in this study opens new avenues for research at the intersection of Islamic ethics, responsible finance and sustainable development and signals the necessity of developing a standardised disclosure index. This index will serve as a vital tool for Takaful operators to transparently communicate their commitment to ethical and sustainable practices, facilitating a deeper understanding of Maqasid-driven ESG integration and bolstering transparency for all stakeholders. Further research into this disclosure index’s practical implementation, empirical validation and strategic implications is encouraged to advance responsible finance within the Takaful industry. Practical implications The proposed blueprint provides Takaful operators with a practical guide to align their operations with both ethical finance and Islamic principles. Embracing the principles of responsible governance, societal welfare and environmental sustainability, Takaful operators can enhance their product offerings, attract socially conscious stakeholders and contribute positively to both financial and ethical objectives. Social implications Integrating Maqasid-driven ESG principles in Takaful signifies a commitment to broader social well-being. Through initiatives aimed at safeguarding life, religion, intellect, lineage and wealth, Takaful operators can play a pivotal role in fostering social cohesion, empowering communities and actively contributing to sustainable development goals. Originality/value This conceptual paper contributes to the field by presenting a unique blueprint for integrating ESG principles within Takaful operations, guided by Maqasid al-Shariah. The novelty of this approach lies in its holistic perspective on ethical finance, aligning Islamic values with contemporary global ethical imperatives. The blueprint offered here represents an original framework for responsible Takaful practices that resonate with evolving ethical standards and the enduring principles of Islamic finance.
Neural networks are becoming very popular with data mining practitioners because they have proven through comparison their predictive power with statistical techniques using real data sets. Based on ...this idea, we will present a method for inducing logical rules from empirical data—Reverse Analysis. When the values of the connections of a neural network resulting from Hebbian learning for the data are given, we hope to know what logical rules are entrenched in it. This method is tested with some real life data sets. In real life data sets, logical rules are assumed to be in conjunctive normal form (CNF) since Horn clauses are inadequate.
The translational accuracy in protein synthesis is contributed to by several mechanisms in the ribosome, generally called kinetic proofreading. This process in the ribosome inhibits the non-cognate ...codon-anticodon interaction. However, it is not sufficient for fidelity of protein synthesis since a wrong amino acid can easily be added to the growing polypeptide chain if a tRNA while cognate to the mRNA, carries a non-cognate amino acid. Therefore, additional to the kinetic proofreading, there must be some hitherto unknown characteristic in misacylated-tRNAs to stop the process of protein synthesis if such misacylated-tRNA is accommodated in the ribosomal A-site. In order to understand this characteristic, we have performed computational quantum chemistry analysis on five different tRNA molecules, each one attached to five different amino acids with one being cognate to the tRNA and the other four non-cognate. This study shows the importance of aminoacyl-tRNA binding energy in ensuring fidelity of protein synthesis.
Notwithstanding various unsolved questions regarding the structure and function of the ribosome, the process of peptide bond formation is of particular importance, being the heart of protein ...synthesis. Several experimental studies have been carried out on the pre- and post-peptidyl transfer structures in the ribosomal active site. Based on these structures, different reaction mechanisms have been proposed and further investigated using computational techniques. However, the detailed mechanism of peptidyl transfer, as well as the atoms and functional groups involved in this process are still in limbo. Although it was suggested that the A2451 is present in the active site of the ribosome in the previous crystallographic structures, the details of its participation have not been fully investigated. Furthermore, despite the highlighted importance of the P-site A76 2′-OH group in previous studies, its actual role during the process is still unclear. Finally, whether the process of peptidyl transfer is a stepwise mechanism or a concerted one is still under debate. Several computational mechanistic studies have been carried out to investigate the catalytic power of the ribosome, yet, they do not cover all the three concerns mentioned above. Therefore, as well as re-investigating the previously proposed reaction mechanisms with a higher level of theory and basis set ( i.e. M06-2X/6-31++G(d,p)//M06-2X/6-311++G(d,p)) in this study, we propose three new reaction mechanisms based on three different pre- and post-peptidyl transfer structures obtained from previous experimental studies. The results of this study highlights the important role played by the P-site A76 2′-OH group in catalyzing the reaction. However, instead of acting as a so-called proton shuttle, this group acts as a polypeptidyl shuttle, transferring the growing polypeptide chain from the leaving 3′-O to the attacking nucleophile through a mechanism known as transesterification. This reaction is aided by the A2451 3′-OH rRNA base, acting as a proton shuttle between the P-site 3′-O and the 2′-O and further stabilizing the transition structure.
Position-sensitive detectors (PSDs) have been used in neutron tomography and nanostructural characterization of material using neutrons that scattered from a monochromator of highly oriented ...pyrolytic graphite type, placed directly in the neutron beam in the Small Angle Neutron Scattering (SANS) facility at the Malaysian Nuclear Agency. PSD uses the
3
He(n,p) reaction to detect neutrons. Because of the
3
He high neutron cross section of 5333 b at 25.3 meV, a PSD is suitable for neutron detection across its axial direction at a low neutron flux of 10
3
cm
−2
-s
−1
. Because of its insensitivity toward gamma radiation, the signals from the PSD for real neutrons are relatively easy to analyze. This paper discusses the use of a PSD in neutron tomography and nanostructural characterization of material in the SANS facility at the Malaysian Nuclear Agency.
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