An in-silico approach to unravel the structure of 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase (DAHPS): a critical enzyme for sennoside biosynthesis in Cassia angustifolia Vahl

Decoding the in-silico structure of isopentenyl Diphosphate Delta-Isomerase protein from Cassia angustifolia Vahl

Senna (Cassia angustifolia Vahl.) is an important medicinal plant used in traditional and modern systems medicine to manage constipation. While various treatment strategies exist, there is growing interest in utilizing traditional herbal medicines like Indian Senna as a natural alternative. Though Isopentenyl Diphosphate Delta-Isomerase (IDI) has been proven to be one of the key enzymes in the sennoside biosynthesis pathway, characterization of it remains largely unexplored. This study aims to bridge the knowledge gap by investigating IDI, an important enzyme involved in sennoside biosynthesis in plants. The study retrieved the coding DNA sequence (CDS) of IDI from Senna transcriptome and successfully cloned and sequenced the gene. Physicochemical properties and secondary structure analysis unveiled protein characteristics, while homology modelling and molecular docking of DMAPP and IPP ligands assessed binding patterns and interactions with caIDI. Notably, Lys37, Arg72, Lys76, Cys88, Ser89, His90, and Lys113 residues engaged with DMAPP, and Arg72, Lys76, Lys113, Ser89, and His90 residues interacted with IPP. Molecular dynamics simulations affirmed protein-ligand complex stability. IPP established sustained hydrogen bonds with Arg72, Ser89, and Lys113; DMAPP sustained interactions with Lys37, Arg72, Ser89, His90 and Lys113. His41, Glu148, Glu150 engaged with magnesium ion; Val77, Thr78 showed dual interactions with IPP, indicating its substrate binding roles. These findings enhance IDI understanding in Indian Senna which not only plays vital role in isoprenoid biosynthesis but also anthraquinone biosynthesis like sennosides.

A review on recent upgradation and strategies to enhance cyclodextrin glucanotransferase properties for its applications

Cyclodextrin glycosyltransferase (CGTase) is a significant extracellular enzyme with diverse functions. CGTase is widely used in production of cyclic α-(1,4)-linked oligosaccharides (cyclodextrins) from starch via transglycosylation reaction. Recent discoveries of novel CGTases from different microorganisms have expanded its applications but natural CGTase have lower yield, leading to heterologous expression for increased production to meet various needs. Moreover, significant advancements in directed evolution approach have been explored to alter the molecular structure of CGTase to enhance its performance. This review comprehensively summarizes the strategies employed in heterologous expression to boost CGTase production and secretion in various host. It also outlines molecular engineering approaches aimed to improving CGTase properties, including product and substrate specificity, catalytic efficiency, and thermal stability. Additionally, a considerable stability against changes in temperature and organic solvents can be obtained by immobilization.