Purification, gene cloning, and biochemical characterization of a β-glucosidase capable of hydrolyzing sesaminol triglucoside from Paenibacillus sp. KB0549

Biochemical and in silico structural properties of a thermo-acid stable β-glucosidase from Beauveria bassiana

β-glucosidase hydrolyses the glycosidic bonds in cellobiose and cello-oligosaccharides, a critical step in the saccharification for biofuel production. Hence, the aim of this study was to gain insights into the biochemical and structural properties of a β-glucosidase from Beauveria bassiana, an entomopathogenic fungus. The β-glucosidase was purified to homogeneity using salt precipitation, ultrafiltration, and chromatographic techniques, attaining a specific activity of 496 U/mg. The molecular mass of the enzyme was then estimated via SDS-PAGE to be 116 kDa, while its activity pattern was confirmed by zymography using 4-methylumbelliferyl-β-d-glucopyranoside. Furthermore, the pH optima and temperature of the enzyme were found to be pH 5.0 and 60 °C respectively; its activity was significantly enhanced by Mg2+ and Na+ and was found to be relatively moderate in the presence of ethanol and dichloromethane. Molecular docking of the modelled B. bassiana β-glucosidase structure with the substrates, viz., 4-nitrophenyl β-d-glucopyranoside and cellobiose, revealed the binding affinity energies of -7.2 and -6.2 (kcal mol-1), respectively. Furthermore, the computational study predicted Lys-657, Asp-658, and Arg-1000 as the core amino acid residues in the catalytic site of the enzyme. This is the first investigation into a purified β-glucosidase from B. bassiana, providing valuable insights into the functional properties of carbohydrases from entomopathogenic fungal endophytes.

Sesame Seeds: A Nutrient-Rich Superfood

Sesame seeds (Sesamum indicum L.) have been cultivated for thousands of years and have long been celebrated for their culinary versatility. Beyond their delightful nutty flavor and crunchy texture, sesame seeds have also gained recognition for their remarkable health benefits. This article provides an in-depth exploration of the numerous ways in which sesame seeds contribute to overall well-being. Sesame seeds are a powerhouse of phytochemicals, including lignans derivatives, tocopherol isomers, phytosterols, and phytates, which have been associated with various health benefits, including the preservation of cardiovascular health and the prevention of cancer, neurodegenerative disorders, and brain dysfunction. These compounds have also been substantiated for their efficacy in cholesterol management. Their potential as a natural source of beneficial plant compounds is presented in detail. The article further explores the positive impact of sesame seeds on reducing the risk of chronic diseases thanks to their rich polyunsaturated fatty acids content. Nevertheless, it is crucial to remember the significance of maintaining a well-rounded diet to achieve the proper balance of n-3 and n-6 polyunsaturated fatty acids, a balance lacking in sesame seed oil. The significance of bioactive polypeptides derived from sesame seeds is also discussed, shedding light on their applications as nutritional supplements, nutraceuticals, and functional ingredients. Recognizing the pivotal role of processing methods on sesame seeds, this review discusses how these methods can influence bioactive compounds. While roasting the seeds enhances the antioxidant properties of the oil extract, certain processing techniques may reduce phenolic compounds.

α-Glucosidase Inhibitors from Cold-Pressed Black Sesame (Sesamum indicum) Meal: Characterization of New Furofuran Lignans, Kinetic Study, and In Vitro Gastrointestinal Digestion

Black sesame (Sesamum indicum) meal is an agricultural waste obtained after oil extraction. It is used as a key protein source in animal feed. Previous investigations have indicated that its health benefits, such as antidiabetic activity, are mainly due to its high lignan content. In the present study, we applied α-glucosidase inhibitory guided isolation to identify the active components responsible for the above claim. Twenty-nine compounds, mostly lignans, were isolated and identified, of which five (2-3, 12-13, and 28) were newly isolated. Of the isolated compounds, 20 and 21 were the most potent inhibitors, retarding enzyme function in noncompetitive and uncompetitive manners. Structure-activity relationship analysis suggested that the number of phenolic hydroxyl groups in the structures was significantly related to the inhibitory effect against α-glucosidase. A gastrointestinal digestion study of the major lignan sesaminol triglucoside (STG, 9) suggested that the transformation of dioxymethylene and glucoside moieties gradually began in the late process, thus enhancing the α-glucosidase inhibitory effect.

Recent status of sesaminol and its glucosides: Synthesis, metabolism, and biological activities

Sesamum indicum is a major and important oilseed crop that is believed to promote human health in many countries, especially in China. Sesame seeds contain two types of lignans: lipid-soluble lignans and water-soluble glucosylated lignans. The major glucosylated lignans are sesaminol glucosides (SGs). So far, four sesaminol isomers and four SGs are identified. During the naturally occurring process of SGs production, sesaminol is generated first from two molecules of E-coniferyl alcohol, and then the sugar is added to the sesaminol one by one, leading to production of SGs. Sesaminol can be prepared from SGs, from sesamolin, and through artificial synthesis. SGs are metabolized in the liver and intestine and are then transported to other tissues. They exhibit several biological activities, most of which are based on their antioxidant and anti-inflammatory activities. In this paper, we present an overview of the current status of research on sesaminol and SGs. We have also discussed their synthesis, preparation, metabolism, and biological activities. It has been suggested that sesaminol and SGs are important biological substances with strong antioxidant properties in vitro and in vivo and are widely used in the food industry, medicine, and cosmetic products. The recovery and utilization of SGs from sesame seed cake after oil processing will generate massive economic benefits.

Structural insights into a bacterial β-glucosidase capable of degrading sesaminol triglucoside to produce sesaminol: toward the understanding of the aglycone recognition mechanism by the C-terminal lid domain

The sesaminol triglucoside (STG)-hydrolyzing β-glucosidase from Paenibacillus sp. (PSTG1), which belongs to glycoside hydrolase family 3 (GH3), is a promising catalyst for the industrial production of sesaminol. We determined the X-ray crystal structure of PSTG1 with bound glycerol molecule in the putative active site. PSTG1 monomer contained typical three domains of GH3 with the active site in domain 1 (TIM barrel). In addition, PSTG1 contained an additional domain (domain 4) at the C-terminus that interacts with the active site of the other protomer as a lid in the dimer unit. Interestingly, the interface of domain 4 and the active site forms a hydrophobic cavity probably for recognizing the hydrophobic aglycone moiety of substrate. The short flexible loop region of TIM barrel was found to be approaching the interface of domain 4 and the active site. We found that n-heptyl-β-D-thioglucopyranoside detergent acts as an inhibitor for PSTG1. Thus, we propose that the recognition of hydrophobic aglycone moiety is important for PSTG1-catalyzed reactions. Domain 4 might be a potential target for elucidating the aglycone recognition mechanism of PSTG1 as well as for engineering PSTG1 to create a further excellent enzyme to degrade STG more efficiently to produce sesaminol.

Iodine values, peroxide values and acid values of Bohai algae oil compared with other oils during the cooking

Objective

Bohai algae oil contains polyunsaturated fatty acids, such as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), which are the very important polyunsaturated fatty acids for the human body. In Traditional Chinese Cooking, all cooking methods cannot do without oils. However, the heat of cooking may always lead to formation of large amounts of decomposition products that affect the sensory, nutritional and functional quality of the oils to be unhealthy and the products being cooked, especially the food or edible oil rich in polyunsaturated fatty acids. Therefore, the objective of this study was to research the effect and change of heating on the quality characteristics of Bohai algae oil comparison with soybean oil and olive oil.

Method

Quality characteristics such as the iodine values (IVs), peroxide values (POVs) and acid values (AVs) of Bohai algae oil, soybean oil and olive oil were measured, cooking conditions as factors of the study.

Result

The POVs percentage changes of Bohai algae oil were larger than the IVs and AVs percentage changes. Bohai algae oil was better heated in a microwave oven at microwave P-20 within 3min, microwave P-60 and P-H1 within 2min, or in induction cooker at 1500w within 1min, or on electric stove (direct heated) within 2min.

Conclusion

Bohai algae oil was suitable used for low-temperature and short-time cooking or for salad. This study has important significance for promoting the commercial value and extensive application of Bohai algae oil in daily cooking. It plays a theoretical significance role in Bohai algae oil's better processing and traditional chinese cooking. It can improve product quality to further expand the food processing research scope of Bohai algae oil and increase the richness, diversity and universality of edible methods of Bohai algae oil.

Suppression of colonic oxidative stress caused by chronic ethanol administration and attenuation of ethanol-induced colitis and gut leakiness by oral administration of sesaminol in mice

Chronic consumption of excess ethanol is one of the major risk factors for colorectal cancer (CRC), and the pathogenesis of ethanol-related CRC (ER-CRC) involves ethanol-induced oxidative-stress and inflammation in the colon and rectum, as well as gut leakiness. In this study, we hypothesised that oral administration of sesaminol, a sesame lignan, lowers the risk of ER-CRC because we found that it is a strong antioxidant with very low prooxidant activity. This hypothesis was examined using a mouse model, in which 2.0% v/v ethanol was administered ad libitum for 2 weeks with or without oral gavage with sesaminol (2.5 mg per day). Oral sesaminol administration suppressed the ethanol-induced colonic lesions and the ethanol-induced elevation of the colonic levels of oxidative stress markers (8-hydroxy-2'-deoxyguanosine, malondialdehyde, and 4-hydroxyalkenals). It consistently suppressed the chronic ethanol-induced expressions of cytochrome P450-2E1 and inducible nitric oxide synthase and upregulated heme oxygenase-1 expression, probably via the nuclear factor erythroid-derived 2-like 2 pathway in the mouse colon. Oral sesaminol administration also suppressed the chronic ethanol-induced elevation of colonic inflammation marker levels, such as those of tumour necrosis factor-α, interleukin-6, and monocyte chemoattractant protein-1, probably via the nuclear factor-kappa B pathway. Moreover, it prevented the chronic ethanol-induced gut leakiness by restoring tight junction proteins, giving rise to lower plasma endotoxin levels compared with those of ethanol-administered mice. All of these results suggest that dietary supplementation of sesaminol may lower the risk of ER-CRC by suppressing each of the above-mentioned steps in ER-CRC pathogenesis.

(+)-Sesamin, a sesame lignan, is a potent inhibitor of gut bacterial tryptophan indole-lyase that is a key enzyme in chronic kidney disease pathogenesis

The progression of chronic kidney disease (CKD) increases the risks of cardiovascular morbidity and end-stage kidney disease. Indoxyl sulfate (IS), which is derived from dietary l-tryptophan by the action of bacterial l-tryptophan indole-lyase (TIL) in the gut, serves as a uremic toxin that exacerbates CKD-related kidney disorder. A mouse model previously showed that inhibition of TIL by 2-aza-l-tyrosine effectively reduced the plasma IS level, causing the recovery of renal damage. In this study, we found that (+)-sesamin and related lignans, which occur abundantly in sesame seeds, inhibit intestinal bacteria TILs. Kinetic studies revealed that (+)-sesamin and sesamol competitively inhibited Escherichia coli TIL (EcTIL) with K_i values of 7 μM and 14 μM, respectively. These K_i values were smaller than that of 2-aza-l-tyrosine (143 μM). Molecular docking simulation of (+)-sesamin- (or sesamol-)binding to EcTIL predicted that these inhibitors potentially bind near the active site of EcTIL, where the cofactor pyridoxal 5'-phosphate is bound, consistent with the kinetic results. (+)-Sesamin is a phytochemical with a long history of consumption and is generally regarded as safe. Hence, dietary supplementation of (+)-sesamin encapsulated in enteric capsules could be a promising mechanism-based strategy to prevent CKD progression. Moreover, the present findings would provide a new structural basis for designing more potent TIL inhibitors for the development of mechanism-based therapeutic drugs to treat CKD.

Enzymatic Preparation and Structure-activity Relationship of Sesaminol

As a valuable natural antioxidant, sesaminol can be used in food and medicine industries, but it is trace in sesame seeds and oil, and it is feasible to prepare sesaminol from sesaminol triglucoside (STG) which is abundant in defatted sesame cake. Therefore, in order to establish an effective enzymatic preparation method and elucidate the antioxidant structure-activity relationship of sesaminol, a suitable glycosidase for preparing sesaminol from STG were screened, enzymatic hydrolysis was optimized by single-factor test and response surface methodology, and finally, the structure-activity relationship of sesaminol was illustrated by comparative molecular field analysis (CoMFA). These results suggested that β-galactosidase was the optimal glycosidase for enzymatic hydrolysis of STG to prepare sesaminol. Under the optimal conditions of a reaction temperature of 50°C, reaction time of 4.0 h, pH of 5.5, substrate concentration of 1.0 mg/mL, and enzyme dosage of 20 mg/mL, the conversion rate of sesaminol was 98.88±0.67%. Sesaminol displayed excellent antioxidant ability in 2,2-diphenyl-1-picrylhydrazyl (DPPH, IC₅₀ = 0.0011 mg/mL), 2,2'-azinobis-(3-ethyl-benzothiazoline-6-sulfonate) (ABTS, IC₅₀ = 0.0021 mg/mL) radical scavenging activities and Ferric reducing antioxidant power (FRAP, 103.2998 mol/g) compared to other sesaminol derivatives. According to －log (IC₅₀ of DPPH) and －log (IC₅₀ of ABTS), CoMFA models were successfully established based on Q₂ >0.5 (Q_DPPH ² = 0.558, Q_ABTS ² = 0.534). The active site of sesaminol tended to be located on the hydroxyl group of the benzene ring (R₁ position). A positive correlation between the bulky and positively charged groups at the 1H, 3H-furo [3, 4-c] furan group, the small, negatively charged groups at the R₁ position and the antioxidant activity of sesaminol. This study provides an effective method to prepare sesaminol, reveals the structure-activity relationship of sesaminol and provides theoretical basis to design the novel compound.

Lignans of Sesame (Sesamum indicum L.): A Comprehensive Review

Major lignans of sesame sesamin and sesamolin are benzodioxol--substituted furofurans. Sesamol, sesaminol, its epimers, and episesamin are transformation products found in processed products. Synthetic routes to all lignans are known but only sesamol is synthesized industrially. Biosynthesis of furofuran lignans begins with the dimerization of coniferyl alcohol, followed by the formation of dioxoles, oxidation, and glycosylation. Most genes of the lignan pathway in sesame have been identified but the inheritance of lignan content is poorly understood. Health-promoting properties make lignans attractive components of functional food. Lignans enhance the efficiency of insecticides and possess antifeedant activity, but their biological function in plants remains hypothetical. In this work, extensive literature including historical texts is reviewed, controversial issues are critically examined, and errors perpetuated in literature are corrected. The following aspects are covered: chemical properties and transformations of lignans; analysis, purification, and total synthesis; occurrence in Seseamum indicum and related plants; biosynthesis and genetics; biological activities; health-promoting properties; and biological functions. Finally, the improvement of lignan content in sesame seeds by breeding and biotechnology and the potential of hairy roots for manufacturing lignans in vitro are outlined.

Molecular modeling, docking and simulation dynamics of β-glucosidase reveals high-efficiency, thermo-stable, glucose tolerant enzyme in Paenibacillus lautus BHU3 strain

The enzyme β-glucosidase mediates the rate limiting step of conversion of cellobiose to glucose and thus plays a vital role in the process of cellulose degradation. The present study deals with analysis of the effective novel strain of Paenibacillus lautus BHU3 for identifying high-efficiency thermostable, glucose tolerant β-glucosidases. Seven counterparts with elevated T_m values ranging from 64.6 to 75.8 °C with high thermo-stability, were revealed through this analysis. The blind molecular docking of the model enzymes structures with cellobiose and pNPG gave high negative interaction energies ranging from -11.33 to -13.29 and -6.43 to -9.054 (kcal mol^-1), respectively. The enzyme WP_096774744.1 effectively formed 5 hydrogen bonds with the highest interaction energy (-13.29 kcal mol^-1) with cellobiose at its catalytic site. Molecular dynamics simulation analysis performed for the WP_096774744.1-pNPG complex predicted Glu5, Arg7, Lue68, Gly69 and Phe325 as the major contributing residues for accomplishing hydrolysis of β-1-4-linkage. Further, the molecular docking of WP_096774744.1 enzyme with glucose revealed a distinct glucose-binding site distant from the substrate-binding site, thus confirming the deficient competitive inhibition by glucose. Hence, WP_096774744.1 β-glucosidase appears to be an efficient enzyme with enhanced activity to biodegrade the cellulosic materials and highly relevant for waste management and various industrial applications.

Sesaminol prevents Parkinson's disease by activating the Nrf2-ARE signaling pathway

Parkinson's disease (PD) is a neurodegenerative disease caused by the degeneration of substantia nigra neurons due to oxidative stress. Sesaminol has strong antioxidant and anti-cancer effects. We investigated the preventive effect on PD as a new physiological action of sesaminol produced from sesaminol glycoside using in vitro and in vivo PD models. To prepare an in vitro PD model, 6-hydroxydopamine (6-OHDA) was added to human neuroblastoma (SH-SY5Y cells). The viability of SH-SY5Y cells decreased dose-dependently following 6-OHDA treatment, but the addition of sesaminol restored viability to the control level. 6-OHDA increased intracellular reactive oxygen species production, and the addition of sesaminol significantly suppressed this increase. No Nrf2 expression in the nucleus was observed in the control group, but a slight increase was observed in the 6-OHDA group. The sesaminol group showed strong expression of Nrf2 in the cytoplasm and nucleus. NAD(P)H: quinone oxidoreductase (NQO1) activity was enhanced in the 6-OHDA group and further enhanced in the sesaminol group. Furthermore, the neurotoxine rotenone was orally administrated to mice to prepare an in vivo PD model. The motor function of rotenone-treated mice was shorter than that of the control group, but a small amount of sesaminol restored it to the control level. The intestinal motility in the rotenone group was significantly lower than that in the control group, but it remained at the control level in the sesaminol group. The expression of α-synuclein in the substantia nigra increased in the rotenone group but decreased in the sesaminol group. The rotenone group exhibited shortening and damage to the colonic mucosa, but these abnormalities of the colonic mucosa were scarcely observed in the sesaminol group. These results suggest that sesaminol has a preventative effect on PD.

Glycoside-specific glycosyltransferases catalyze regio-selective sequential glucosylations for a sesame lignan, sesaminol triglucoside

Sesame (Sesamum indicum) seeds contain a large number of lignans, phenylpropanoid-related plant specialized metabolites. (+)-Sesamin and (+)-sesamolin are major hydrophobic lignans, whereas (+)-sesaminol primarily accumulates as a water-soluble sesaminol triglucoside (STG) with a sugar chain branched via β1→2 and β1→6-O-glucosidic linkages [i.e. (+)-sesaminol 2-O-β-d-glucosyl-(1→2)-O-β-d-glucoside-(1→6)-O-β-d-glucoside]. We previously reported that the 2-O-glucosylation of (+)-sesaminol aglycon and β1→6-O-glucosylation of (+)-sesaminol 2-O-β-d-glucoside (SMG) are mediated by UDP-sugar-dependent glucosyltransferases (UGT), UGT71A9 and UGT94D1, respectively. Here we identified a distinct UGT, UGT94AG1, that specifically catalyzes the β1→2-O-glucosylation of SMG and (+)-sesaminol 2-O-β-d-glucosyl-(1→6)-O-β-d-glucoside [termed SDG(β1→6)]. UGT94AG1 was phylogenetically related to glycoside-specific glycosyltransferases (GGTs) and co-ordinately expressed with UGT71A9 and UGT94D1 in the seeds. The role of UGT94AG1 in STG biosynthesis was further confirmed by identification of a STG-deficient sesame mutant that predominantly accumulates SDG(β1→6) due to a destructive insertion in the coding sequence of UGT94AG1. We also identified UGT94AA2 as an alternative UGT potentially involved in sugar-sugar β1→6-O-glucosylation, in addition to UGT94D1, during STG biosynthesis. Yeast two-hybrid assays showed that UGT71A9, UGT94AG1, and UGT94AA2 were found to interact with a membrane-associated P450 enzyme, CYP81Q1 (piperitol/sesamin synthase), suggesting that these UGTs are components of a membrane-bound metabolon for STG biosynthesis. A comparison of kinetic parameters of these UGTs further suggested that the main β-O-glucosylation sequence of STG biosynthesis is β1→2-O-glucosylation of SMG by UGT94AG1 followed by UGT94AA2-mediated β1→6-O-glucosylation. These findings together establish the complete biosynthetic pathway of STG and shed light on the evolvability of regio-selectivity of sequential glucosylations catalyzed by GGTs.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2013-2014

This review is the eighth update of the original article published in 1999 on the application of Matrix-assisted laser desorption/ionization mass spectrometry (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2014. Topics covered in the first part of the review include general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation, and arrays. The second part of the review is devoted to applications to various structural types such as oligo- and poly- saccharides, glycoproteins, glycolipids, glycosides, and biopharmaceuticals. Much of this material is presented in tabular form. The third part of the review covers medical and industrial applications of the technique, studies of enzyme reactions, and applications to chemical synthesis. © 2018 Wiley Periodicals, Inc. Mass Spec Rev 37:353-491, 2018.

Identification and characterization of a novel bacterial β-glucosidase that is highly specific for the β-1,2-glucosidic linkage of sesaminol triglucoside

A gene (PSTG2) coding for a novel β-glucosidase belonging to glycoside hydrolase family 3 was identified in the vicinity of the previously identified β-glucosidase gene [sesaminol triglucoside (STG)-hydrolyzing β-glucosidase, PSTG1] in the genome of Paenibacillus sp. strain KB0549. Compared with PSTG1, recombinant PSTG2 more specifically acted on the β-1,2-glucosidic linkage of the STG molecule to transiently accumulate a larger amount of 6-O-(β-D-glucopyranosyl)-β-D-glucopyranosylsesaminol.

Paenibacillus relictisesami sp. nov., isolated from sesame oil cake

A facultatively anaerobic, Gram-stain-positive, rod-shaped bacterium, designated strain KB0549T, was isolated from sesame oil cake. Cells were motile, round-ended rods, and produced central or terminal spores. The cell wall peptidoglycan contained meso-diaminopimelic acid as the diamino acid. The major fatty acids were anteiso-C15:0 and anteiso-C17:0. The DNA G+C content of strain KB0549T was 51.9 mol%. On the basis of 16S rRNA gene sequence phylogeny, strain KB0549T was affiliated with the genus Paenibacillus in the phylum Firmicutes and was most closely related to Paenibacillus cookii with 97.4% sequence similarity. Strain KB0549T was physiologically differentiated from P. cookii by the high content of anteiso-C17:0, inability to grow at 50 °C, spore position, and negative Voges-Proskauer reaction. Based on these unique physiological and phylogenetic characteristics, it is proposed that the isolate represents a novel species, Paenibacillus relictisesami sp. nov.; the type strain is KB0549T (=JCM 18068T=DSM 25385T).