Purification and characterization of a novel glycoprotein from Streptomyces sp. ZX01

Glycoprotein from Sargassum fusiforme exhibiting anti-inflammatory responses in vitro and in vivo via modulation of TLR4/MyD88 and NF-κB signaling

This study focuses on the identification and characterization of a glycoprotein from Sargassum fusiforme (Harvey) Setchell (SFGP), as well as investigating its potential anti-inflammatory properties both in vitro and in vivo, along with the underlying mechanism. SDS-PAGE analysis revealed a prominent band with a molecular weight of <10 kDa, consisting of 58.39 % protein and 41.61 % carbohydrates, which was confirmed through glycoprotein staining and Coomassie blue staining. Various analytical techniques, including high-resolution mass spectrometry (HRMS), FTIR, amino acid analysis, and UV-visible spectrometry, provided evidence for the presence of monosaccharides (such as d-glucose and mannose) and 17 amino acids linked by an O-glycopeptide bond. In vitro and in vivo studies were conducted to assess the anti-inflammatory activities of SFGP. The results demonstrated that SFGP effectively attenuated nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expressions in LPS-treated RAW264.7 cells. Moreover, SFGP administration significantly and dose-dependently suppressed TLR4/MyD88 signaling as well as the phosphorylation of MAPKs, IκB, and NF-κB, leading to a reduction in the production of TNF-α, IL-1β, and IL-6 in LPS-stimulated RAW264.7 cells. Furthermore, the anti-inflammatory efficacy of SFGP was validated in a carrageenan-induced inflammatory mouse model. These findings indicate that SFGP exhibits anti-inflammatory characteristics and has the potential to be utilized as a novel anti-inflammatory agent.

Insight into the soil bacterial community succession of Nicotiana benthamiana in response to Tobacco mosaic virus

Background

Tobacco mosaic virus (TMV) is one famous plant virus responsible for substantial economic losses worldwide. However, the roles of bacterial communities in response to TMV in the tobacco rhizosphere remain unclear.

Methods

We explored the soil physicochemical properties and bacterial community succession of the healthy (YTH) and diseased (YTD) plants with TMV infection by 16S rRNA gene sequencing and bioinformatics analysis.

Results

We found that soil pH in the YTD group was significantly lower than in the YTH group, and the soil available nutrients were substantially higher. The bacterial community analysis found that the diversity and structure significantly differed post-TMV disease onset. With TMV inoculated, the alpha diversity of the bacterial community in the YTD was markedly higher than that in the YTH group at the early stage. However, the alpha diversity in the YTD group subsequently decreased to lower than in the YTH group. The early bacterial structure of healthy plants exhibited higher susceptibility to TMV infection, whereas, in the subsequent stages, there was an enrichment of beneficial bacterial (e.g., Ramlibacter, Sphingomonas, Streptomyces, and Niastella) and enhanced energy metabolism and nucleotide metabolism in bacteria.

Conclusion

The initial soil bacterial community exhibited susceptibility to TMV infection, which might contribute to strengthening resistance of Tobacco to TMV.

Purification and characterization of a glycoprotein from Sipunculus nudus and its immune-enhancing activity to RAW 264.7 macrophages

Sipunculus nudus, an edible marine invertebrate, has long been used as traditional Chinese medicine in folk remedies. In order to assess the immunoregulatory activity of glycoproteins in Sipunculus nudus and conduct a structure-activity relationship, a glycoprotein (SGP1) with molecular mass of 9.26 kDa was purified from Sipunculus nudus, and its chemical structure as well as immune-enhancing activity was investigated in this study. Structure analysis revealed that SGP1, a protein-dominate glycoprotein with O-glycosidic bonds, contained 92.8 % protein and 3.1 % saccharide. GC-MS result indicated that the saccharide moieties of SGP1 basically consisted of lyxose (Lyx), xylose (Xyl) as well as glucose (Glu) at a molar proportion of 0.87:4.16:1.36. The fourier transform infrared specoscopy (FT-IR) result proved that SGP1 have a typical characteristic of glycoprotein. Besides, circular dichroism (CD) result showed that SGP1 contained 4.1 % α-helix, 42.5 % β-sheet, 21.4 % β-turn, and 32.0 % random coil, indicating it's mainly a β-sheet glycoprotein. The amino acid sequence of SGP1 shared a similarity to the Myohemerythrin (sp|Q5K473|HEMTM) with protein sequence coverage of 28.3 %. Moreover, the activity evaluation results showed that SGP1 exhibited significant immune-enhancing activity to the RAW 264.7 macrophages by promoting macrophages proliferation, enhancing phagocytic capacity, and simultaneously stimulating the secretions of nitric oxide (NO), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) via NF-κB pathways. In this study, SGP1 as a novel glycoprotein had an obvious immune-enhancing activity to macrophages, and thus could be applied in the functional foods as a potential immunopotentiator for the hypoimmune population.

Structure and Antidiabetic Activity of a Glycoprotein from Porphyra haitanensis

A novel antidiabetic glycoprotein (PG) was isolated and purified from Porphyra haitanensis, and its structure and inhibiting activity on α-amylase and α-glucosidase were analyzed. The purity of the PG was 95.29 ± 0.21%, and its molecular weight was 163.024 ± 5.55 kDa. The PG had a tetramer structure with α- and β-subunits, and it contained 54.12 ± 0.86% protein (with highly hydrophobic amino acids) and 41.19% ± 0.64% carbohydrate (composed of galactose). The PG was linked via an O-glycosidic bond, exhibiting an α-helical structure and high stability. In addition, the PG inhibited the activities of α-amylase and α-glucosidase, by changing the enzyme's structure toward the PG's structure in a noncompetitive inhibition mode. Molecular docking results showed that the PG inhibited α-amylase activity by hydrophobic interaction, whereas it inhibited α-glucosidase activity by hydrogen bonds and hydrophobic interaction. Overall, the PG was linked to polysaccharides via O-glycosidic bonds, showing an α-helical configuration and a hydrophobic effect, which altered the configuration of α-amylase and α-glucosidase and exerted hypoglycemic activity. This study provides insights into analyzing the structure and antidiabetic activity of glycoproteins.

Limonene anti-TMV activity and its mode of action

The main component of orange peel essential oil is limonene. Limonene is a natural active monoterpene with multiple functions, such as antibacterial, antiseptic and antitumor activity, and has important development value in agriculture. This study found that limonene exhibited excellent anti-tobacco mosaic virus (TMV) bioactivity, with results showing that its protection activity, inactivation activity, and curative activity at 800 μg/mL were 84.93%, 59.28%, and 58.89%, respectively-significantly higher than those of chito-oligosaccharides. A direct effect of limonene on TMV particles was not observed, but limonene triggered the hypersensitive response (HR) in tobacco. Further determination of the induction activity of limonene against TMV demonstrated that it displayed good induction activity at 800 μg/mL, with a value of 60.59%. The results of physiological and biochemical experiments showed that at different treatment days, 800 μg/mL limonene induced the enhancement of defense enzymes activity in tobacco, including of SOD, CAT, POD, and PAL, which respectively increased by 3.2, 4.67, 4.12, and 2.33 times compared with the control (POD and SOD activities reached highest on the seventh day, and PAL and CAT activities reached highest on the fifth day). Limonene also enhanced the relative expression levels of pathogenesis related (PR) genes, including NPR1, PR1, and PR5, which were upregulated 3.84-fold, 1.86-fold and 1.71-fold, respectively. Limonene induced the accumulation of salicylic acid (SA), and increased the relative expression levels of genes related to SA biosynthesis (PAL) and reactive oxygen species (ROS) burst (RBOHB), which respectively increased by 2.76 times and 4.23 times higher than the control. Systemic acquired resistance (SAR) is an important plant immune defense against pathogen infection. The observed accumulation of SA, the enhancement of defense enzymes activity and the high-level expression of defense-related genes suggested that limonene may induce resistance to TMV in tobacco by activating SAR mediated by the SA signaling pathway. Furthermore, the experimental results demonstrated that the expression level of the chlorophyll biosynthesis gene POR1 was increased 1.72-fold compared to the control in tobacco treated with 800 μg/mL limonene, indicating that limonene treatment may increase chlorophyll content in tobacco. The results of pot experiment showed that 800 μg/mL limonene induced plant resistance against Sclerotinia sclerotiorum (33.33%), Phytophthora capsici (54.55%), Botrytis cinerea (50.00%). The bioassay results indicated that limonene provided broad-spectrum and long-lasting resistance to pathogen infection. Therefore, limonene has good development and utilization value, and is expected to be developed into a new botanical-derived anti-virus agent and plant immunity activator in addition to insecticides and fungicides.

Isolation, structures and biological activities of medicinal glycoproteins from natural resources: A review

In recent years, natural resources have proven to be tremendous sources of glycoproteins. As biological macromolecules, glycoproteins are essential to the growth and development of organisms, and have attracted increasing attention around the world. This review summarized and discussed the development of glycoproteins from natural resources, including isolation methods, purification processes, structural features and biological activities. Generally, the vast majority of glycoproteins can be isolated by hot water extraction followed by purification through gel filtration chromatography. Combined with component analysis, the physicochemical properties of glycoproteins are studied by using several spectroscopic techniques such as ultraviolet-visible (UV-Visible), Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR). Moreover, natural glycoproteins possess various remarkable biological activities, including anti-tumor, anti-oxidant, anti-coagulant and anti-microbial activities. The content of this review will provide a theoretical basis for the research on related glycoproteins and give a perspective on the use of these medical resources.

Mechanisms of Microbial Plant Protection and Control of Plant Viruses

Plant viral diseases are major constraints causing significant yield losses worldwide in agricultural and horticultural crops. The commonly used methods cannot eliminate viral load in infected plants. Many unconventional methods are presently being employed to prevent viral infection; however, every time, these methods are not found promising. As a result, it is critical to identify the most promising and sustainable management strategies for economically important plant viral diseases. The genetic makeup of 90 percent of viral diseases constitutes a single-stranded RNA; the most promising way for management of any RNA viruses is through use ribonucleases. The scope of involving beneficial microbial organisms in the integrated management of viral diseases is of the utmost importance and is highly imperative. This review highlights the importance of prokaryotic plant growth-promoting rhizobacteria/endophytic bacteria, actinomycetes, and fungal organisms, as well as their possible mechanisms for suppressing viral infection in plants via cross-protection, ISR, and the accumulation of defensive enzymes, phenolic compounds, lipopeptides, protease, and RNase activity against plant virus infection.

A glycoprotein from mountain cultivated ginseng: Insights into their chemical characteristics and intracellular antioxidant activity

A glycoprotein (MGP2) from mountain-cultivated ginseng (MCG) was purified by Tris-HCl extraction followed by DEAE-52 ion exchange chromatography and Sephadex G-100 gel filtration chromatography. The approximate molecular weight (27.0 kDa) and monomeric nature were determined by reduced and non-reduced SDS-PAGE. The structure of MGP2 was characterized by a practical and reliable "protein-polysaccharide analyzed by spectroscopy combined with chemical analysis" strategy. The results showed that MGP2 belonged to Arabinogalactan proteins (AGPs) which contained high amount of Glc (35.1 %). The hemagglutination test concluded that MGP2 was not a lectin. In addition, the MGP2 exhibited antioxidant activity by scavenging radical capacity tests and the ability to protect human erythrocytes and RAW264.7 cells from oxidative damage induced by AAPH. Therefore, these results suggested that glycoprotein MGP2 could be used as a natural antioxidant in drug and food industry.

Two glycoproteins from medicinal insect Periplaneta americana (L.) promote diabetic wound healing via macrophage polarization modulation

Along with the increasing attempts to explore the wound healing effective substances of Periplaneta americana (L.) (PA), a medicinal insect in traditional Chinese medicine, researchers' attention turned to the endogenetic macromolecules, such as polysaccharides and peptides. Herein, we innovatively isolated two glycoproteins from PA, named PAGP-1 and PAGP-2, which were obtained by Cellulose DE-52 chromatography and purified by Sephadex G-100 gel in succession. The structural characterization of the two PAGPs were performed, including molecular weight, amino acid and monosaccharide composition, morphology analysis, FT-IR and ¹H NMR analysis, CD spectroscopy, and glycosides linkage. As a result, two PAGPs belonged to O-glycopeptide bonds linked glycoproteins. The content of carbohydrate and protein of PAGP-1 was approximately 25.23% and 65.92% respectively, which of PAGP-2 was approximately 25.71% and 71.23%. Based on the remarkable anti-inflammatory effects of PAGPs on LPS-induced RAW264.7 cells, the topical administration of PAGP-1 and PAGP-2 could significantly accelerate full-thickness wound healing in diabetic mice, involving to alleviate the inflammation, increase the ratio of type I and type III collagen fibers, and promote the polarization of macrophages M1 to M2. In short, this study provides clear evidence that the glycoproteins would be the potential wound healing bioactive substances in PA.

Effects of indole derivatives from Purpureocillium lilacinum in controlling tobacco mosaic virus

There are various types of compounds studied and applied for plant disease management, and some of them are environment friendly and suitable in organic production. An example is indole-3-carboxaldehyde (A1) and indole-3-carboxylic acid (A2) derived from Purpureocillium lilacinum H1463, which have shown a strong activity in the control of tobacco mosaic virus (TMV). In this study, the effects of these compounds were studied on suppressing TMV and corresponding mechanism. Both A1 and A2 exhibited strong anti-TMV activities in vitro and in vivo. They fractured TMV virions and forced the fractured particles agglomerated. A1 and A2 also induced immune responses or resistance of tobacco to TMV infection, including expressing hypersensitive reaction (HR), increasing defense-related enzymes and overexpressing pathogenesis-related (PR) proteins. The upregulation of salicylic acid (SA) biosynthesis genes PAL, ICS, and PBS3 confirmed that SA served as a defense-related signal molecule. Therefore, indole derivatives have a potential for activating defense of tobacco against TMV and other pathogens and can be used for disease control.

Evaluation of the Effectiveness of Soil Streptomyces Isolates for Induction of Plant Resistance Against Tomato mosaic virus (ToMV)

The ability of various Streptomyces isolates obtained from soil to induce systemic resistance in tomato (Solanum lycopersicum cv. Supra) plant against Tomato mosaic virus (ToMV) was characterized in current study. Importantly, of nine Streptomyces isolates tested herein, the culture filtrate (CF) of one isolate, designated as Streptomyces ovatisporus LC597360, was the most effective. It exhibited 93.9% biocontrol efficacy and induced a significant decrease (17.6 ± 0.8%) of symptoms severity compared with infected control plants. These finding were confirmed using I-ELISA showing that ToMV concentration was significantly reduced in plants treated with S. ovatisporus LC597360 CF as compared with plants inoculated with ToMV. Moreover, treatment with CF of S. ovatisporus LC597360 not only increased activity of defense-related enzymes such as ascorbate oxidase, catalase, peroxidase, and polyphenol oxidase, but also induced plant growth promotion. The present study is the first one that demonstrates the potential of S. ovatisporus LC597360 in biocontrol of ToMV and investigated its antiviral mechanisms.

H2O2 signaling modulates Glycoprotein-1 induced programmed cell death in tobacco suspension cells

Glycoprotein (GP)-1 is a glycoprotein elicitor with antiviral activity found in Streptomyces kanasensis zx01. GP-1 can induce programmed cell death (PCD) in vitro; however, the underlying mechanism is unclear. In the present study, we demonstrated that GP-1 induced PCD in tobacco suspension cells, which was modulated by hydrogen peroxide (H2O2). GP-1 participated in and modulated biologically relevant signaling in plant cells. GP-1 induced tobacco cell death in a dose- and time-dependent manner; affected the expression of BRI1-associated receptor kinase 1 (BAK1) and the accumulation of salicylic acid (SA), which are related to PCD; and enzymatic activities and mitochondrial functions. In conclusion, GP-1-induced PCD in tobacco may be mediated by H2O2 which alters BAK1 and SA levels, as well as mitochondrial and gene function. This cell signal cascade played an important role in the process of GP-1 induced plant disease resistance.

A novel glycoprotein from Streptomyces sp. triggers early responses of plant defense

GP-1, a novel glycoprotein from Streptomyces sp. ZX01 has a plant immunity-inducing effect. GP-1-treated plants exhibited enhanced systemic resistance with a significant reduction in TMV lesions on tobacco leaves, but its antiviral mechanism remains unclear. In this study, early plant defense-related responses, such as Ca2+ influx, callose apposition, oxidative burst, hypersensitive response, programmed cell death, increase in nitric oxide (NO), and stomatal closure, were investigated under GP-1 treatment, and the mechanism of how GP-1 induces viral resistance in Nicotiana benthamiana was studied. Results showed that GP-1 induced [Ca2+]cyt rapidly in tobacco leaves and suspended cells, followed by reactive oxygen species (ROS) and NO elevation. Transcriptome analysis showed significant differences in expression levels between the GP-1-treated N. benthamiana and the control and showed significantly upregulated and enriched pathways including defense and immune reaction. Similar to typical pathogen-associated molecular patterns, GP-1 induced callose deposition and stomatal closure to form defense barriers against pathogen invasion. The expression of defense-related genes further confirmed the above conclusions. By analyzing transcriptome in N. benthamiana and the contents of salicylic acid (SA) and jasmonic acid (JA), GP-1 enhanced viral resistance of tobacco by improving the SA and JA contents, strengthening plant secondary metabolites activities, promoting systemic accumulation of pathogenesis-related proteins in TMV- inoculated tobacco there by producing antiviral activity.

Studies on the effect of a Fupenzi glycoprotein on the fibrillation of bovine serum albumin and its antioxidant activity

In this study, the effect of a glycoprotein obtained from Fupenzi (FPZ) (Rubus chingii Hu.) on the fibrillation of bovine serum album (BSA) was investigated by multi-spectroscopic methods and transmission electron microscopy. Moreover, the cytotoxicity of the glycoprotein and the effect of it on H₂O₂-induced cell viability were investigated by cell counting kit and β-galactosidase kit, respectively. The experimental results indicated that the glycoprotein showed very low toxicity to NRK-52E cells and could obviously delay cell senescence and improve cell viability. Moreover, the glycoprotein could effectively inhibit the formation of BSA fibrils and destroy the stability of preformed BSA fibrils in a concentration-dependent manner. Generally, antioxidant capacities are thought to be related to the anti-amyloidogenic activity of inhibitors; therefore, to reveal the inhibitory mechanism, the anti-oxidative property of the glycoprotein was examined by DPPH and ABTS assays. The results demonstrated that FPZ glycoprotein had a remarkable antioxidant activity and the IC₅₀ values of DPPH and ABTS were 0.249 mg mL^-1 and 0.092 mg mL^-1, respectively. This work suggested that the FPZ glycoprotein had the potential to be designed a new therapeutic agent for attenuating aging and preventing the age-related diseases.

High bioreactor production and emulsifying activity of an unusual exopolymer by Chromohalobacter canadensis 28

Unusual composition of an exopolymer (EP) from an obligate halophilic bacterium Chromohalobacter canadensis 28 has triggered an interest in development of an effective bioreactor process for its production. Its synthesis was investigated in 2-L bioreactor at agitation speeds at interval 600-1000 rpm, at a constant air flow rate of 0.5 vvm; aeration rates of 0.5, 1.0, and 1.5 vvm were tested at constant agitation rate of 900 rpm. EP production was affected by both, agitation and aeration. As a result twofold increase of EP yield was observed and additionally increased up to 3.08 mg/mL in a presence of surfactants. For effective scale-up of bioreactors mass transfer parameters were estimated and lowest values of KLa obtained for the highest productivity fermentation was established. Emulsification activity of EP exceeded that of trade hydrocolloids xanthan, guar gum, and cellulose. A good synergism between EP and commercial cellulose proved its potential exploration as an enhancer of emulsifying properties of trade emulsions. A pronounced lipophilic effect of EP was established toward olive oil and liquid paraffin. Cultivation of human keratinocyte cells (HaCaT) with crude EP and purified γ-polyglutamic acid (PGA) showed higher viability than control group.

Homology analysis of 35 β-glucosidases in Oenococcus oeni and biochemical characterization of a novel β-glucosidase BGL0224

β-Glucosidases play an important role in food industry. Oenococcus oeni are typical lactic acid bacteria that initiate malolactic fermentation of wines. 35 β-glucosidases from O. oeni were selected and their conserved domains and evolutionary relationships were further explored in this study. The homology analysis results indicated that 35 β-glucosidases were basically derived from GH1 and GH3 family. A novel β-glucosidase was successfully expressed and characterized. The recombinant protein, referred to as BGL0224, consisted of a total 480 amino acids with an apparent molecular weight of 55.15 kDa and was classified as GH1 family. It achieved the highest activity at pH 5.0 and 50 °C. The activity and stability were significantly increased when 12% ethanol was supplemented to the enzyme. Using p-NPG as substrate, the K_m, V_max and K_cat of BGL0224 were 0.34 mM, 382.81 U/mg and 351.88 s^-1, respectively. In all, BGL0224 has good application prospects in food industry.

Extraction, purification, characterization, and rheological properties of a glycoprotein from Cynomorium songaricum Rupr

Cynomorium songaricum Rupr is widely known in China as a traditional herbal medicine. In this study, single-factor experiments and response surface methodology were used to optimize the extraction of Cynomorium songaricum Rupr glycoprotein (CSG). The results show that a maximum glycoprotein yield of 6.39 ± 0.32% was achieved at a ratio of solid to liquid 32:1 for 4.2 H at 52 °C. Then, the IR, monosaccharide composition, amino acid composition, type of glycopeptide linkage, and average molecular weight of CSG-1 purified from CSG were characterized. The results indicate that CSG-1 presented the characteristic absorption peak of polysaccharide and protein, including four monosaccharides and 17 amino acids, had O-linked glycopeptide bonds, M_w , W_n , M_w /M_n , M_p , and the z-average were 5.343 × 10⁶ , 3.203 × 10⁶ , 1.668, 8.911 × 10⁶ , and 6.948 × 10⁶ , respectively. Besides, CSG-1 solution was described by the Herschel-Bulkley model and it behaved as a shear-thinning fluid. Also, under a frequency sweep the moduli G' and G″ both increased with increasing CSG-1 concentration and the CSG-1 dispersions had weak thermal stability over the temperature sweep. These results provide a scientific basis for the further study of Cynomorium songaricum Rupr.

Isolation and Characterization of a Novel Sialoglycopeptide Promoting Osteogenesis from Gadus morhua Eggs

Gadus morhua eggs contain several nutrients, including polyunsaturated fatty acids, lecithin and glycoproteins. A novel sialoglycopeptide from the eggs of G. morhua (Gm-SGPP) was extracted with 90% phenol and purified by Q Sepharose Fast Flow (QFF) ion exchange chromatography, followed by S-300 gel filtration chromatography. Gm-SGPP contained 63.7% carbohydrate, 16.2% protein and 18.6% N-acetylneuraminic acid. High-performance size exclusion chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that Gm-SGPP is a 7000-Da pure sialoglycopeptide. β-elimination reaction suggested that Gm-SGPP contained N-glycan units. Amino acid N-terminal sequence analysis indicated the presence of Ala-Ser-Asn-Gly-Thr-Gln-Ala-Pro amino acid sequence. Moreover, N-glycan was connected at the third Asn location of the peptide chain through GlcNAc. Gm-SGPP was composed of D-mannose, D-glucuronic acid and D-galactose. Fourier transform-infrared spectroscopy (FT-IR), ¹H-nuclear magnetic resonance spectroscopy (¹H-NMR) and methylation analysis were performed to reveal the structure profile of Gm-SGPP. In vitro results showed that the proliferation activity of MC3T3-E1 cells was significantly promoted by Gm-SGPP. In vivo data revealed that Gm-SGPP increased the calcium and phosphorus content of tibias and promoted longitudinal bone growth in adolescent rats.

Purification, characterization, and functional properties of a novel glycoprotein from tartary buckwheat (Fagopyrum tartaricum) seed

A pure glycoprotein (BGP4-I) was obtained from tartary buckwheat seeds by aqueous extraction followed by DEAE-Sepharose Fast Flow ion exchange chromatography and Sephadex G-100 gel filtration chromatography. The average molecular weight of BGP4-I, as determined by high performance gel permeation chromatography, was 123.43 kDa. The structure of BGP4-I was characterized based on Fourier transform infrared spectroscopy, circular dichroism spectroscopy, and nuclear magnetic resonance spectroscopy, etc. Based on the nano-liquid chromatography-coupled electrospray ionization mass spectrometry analysis of the amino acid sequence of BGP4-I, belongs unequivocally to the glycosyl hydrolase family 1 in the Carbohydrate Active Enzymes database by alignment studies. The specific activity of BGP4-I was 18.44 μmol/min/mg on the substrate p-nitrophenyl-β-d-glucopyranoside. Furthermore, BGP4-I is unique in its specificity for some substrates. These results suggest that the BGP4-I from tartary buckwheat seeds is a novel specific β-glucosidase setting the foundation for potential applications in the food industry.

Characterizing bacterial glycoproteins with LC-MS

INTRODUCTION

Though eukaryotic glycoproteins have been studied since their discovery in the 1930s, the first bacterial glycoprotein was not identified until the 1970s. As a result, their role in bacterial pathogenesis is still not well understood and they remain an understudied component of bacterial virulence. In recent years, mass spectrometry has emerged as a leading technology for the study of bacterial glycoproteins, largely due to its sensitivity and versatility. Areas covered: Identification and comprehensive characterization of bacterial glycoproteins usually requires multiple complementary mass spectrometry approaches, including intact protein analysis, top-down analysis, and bottom-up methods used in combination with specialized liquid chromatography. This review provides an overview of liquid chromatography separation technologies, as well as current and emerging mass spectrometry approaches used specifically for bacterial glycoprotein identification and characterization. Expert commentary: Bacterial glycoproteins may have significant clinical utility as a result of their unique structures and exposure on the surface of the cells. Better understanding of these glycoconjugates is an essential first step towards that goal. These often unique structures, and by extension the key enzymes involved in their synthesis, represent promising targets for novel antimicrobials, while unique carbohydrate structures may be used as antigens in vaccines or as biomarkers.

Effects of Agitation, Aeration and Temperature on Production of a Novel Glycoprotein GP-1 by Streptomyces kanasenisi ZX01 and Scale-Up Based on Volumetric Oxygen Transfer Coefficient

The effects of temperature, agitation and aeration on glycoprotein GP-1 production by Streptomyces kanasenisi ZX01 in bench-scale fermentors were systematically investigated. The maximum final GP-1 production was achieved at an agitation speed of 200 rpm, aeration rate of 2.0 vvm and temperature of 30 °C. By using a dynamic gassing out method, the effects of agitation and aeration on volumetric oxygen transfer coefficient (k_La) were also studied. The values of volumetric oxygen transfer coefficient in the logarithmic phase increased with increase of agitation speed (from 14.53 to 32.82 h⁻¹) and aeration rate (from 13.21 to 22.43 h⁻¹). In addition, a successful scale-up from bench-scale to pilot-scale was performed based on volumetric oxygen transfer coefficient, resulting in final GP-1 production of 3.92, 4.03, 3.82 and 4.20 mg/L in 5 L, 15 L, 70 L and 500 L fermentors, respectively. These results indicated that constant volumetric oxygen transfer coefficient was appropriate for the scale-up of batch fermentation of glycoprotein GP-1 by Streptomyces kanasenisi ZX01, and this scale-up strategy successfully achieved 100-fold scale-up from bench-scale to pilot-scale fermentor.

Optimization of Fermentation Conditions and Bench-Scale for Improvement of a Novel Glycoprotein GP-1 Production by Streptomyces kanasenisi ZX01

GP-1 is a novel glycoprotein produced by Streptomyces kanasenisi ZX01 that was isolated from soil near Kanas Lake with significant bioactivity against tobacco mosaic virus. However, extremely low fermentation production has largely hindered further research and market applications on glycoprotein GP-1. In this study, response surface methodology was used to optimize fermentation conditions in a shake flask for higher glycoprotein GP-1 production. When the optimized fermentation conditions were inoculum volume of 6%, initial pH of 6.5, and rotating speed of 150 rpm, glycoprotein GP-1 production could reach 0.9253 mg/L, which was increased by 52.14% compared to the original conditions. In addition, scale-up fermentation was conducted in a 5-L bioreactor to preliminarily explore the feasibility for mass production of glycoprotein GP-1 in a large fermentor, obtaining GP-1 production of 2.54 mg/L under the same conditions, which was 2.75 times higher than the production obtained from a shake flask of 0.9253 mg/L. This work will be helpful to improve GP-1 production on a large scale and lay the foundations for developing it as a novel agent against plant virus.

Optimization of medium compositions to improve a novel glycoprotein production by Streptomyces kanasenisi ZX01

Streptomyces kanasenisi ZX01 was found to produce a novel glycoprotein GP-1 previously, which was secreted into medium and had significant activity against tobacco mosaic virus. However, the low production of GP-1 by strain ZX01 limited its further studies. In order to improve the yield of GP-1, a series of statistical experimental design methods were applied to optimize medium of strain ZX01 in this work. Millet medium was chosen to be the optimal original medium for optimization. Soluble starch and yeast extract were identified as the optimal carbon and nitrogen source using one-factor-at-a-time method. Response surface methodology was used to optimize medium compositions (soluble starch, yeast extract and inorganic salts). A higher yield of GP-1 was 601.33 µg/L after optimization. The optimal compositions of medium were: soluble starch 13.61 g/L, yeast extract 4.19 g/L, NaCl 3.54 g/L, CaCO3 0.28 g/L, millet, 10 g/L. The yield of GP-1 in a 5 L fermentor using optimized medium was 2.54 mg/L, which is much higher than the result of shake flask. This work will be helpful for the improvement of GP-1 production on a large scale and lay a foundation for developing it to be a novel anti-plant virus agent.

Genome-Wide Analysis Reveals the Secondary Metabolome in Streptomyces kanasensis ZX01

Streptomyces kanasensis ZX01 produces some antibiotics and a glycoprotein with antiviral activity. To further evaluate its biosynthetic potential, here we sequenced the 7,026,279 bp draft genome of S. kanasensis ZX01 and analyzed all identifiable secondary gene clusters for controlling natural products. More than 60 putative clusters were found in S. kanasensis ZX01, the majority of these biosynthetic loci are novel. In addition, the regulators for secondary metabolism in S. kanasensis ZX01 were abundant. The global regulator nsdA not only controls biosynthesis of some antibiotics, but also enhances production of glycoprotein GP-1 with antiviral activity. This study importantly reveals the powerful interplay between genomic analysis and studies of traditional natural product purification/production increasing.

Advances and prospects in biogenic substances against plant virus: A review

Plant virus diseases, known as 'plant cancer', are the second largest plant diseases after plant fungal diseases, which have caused great damage to agricultural industry. Since now, the most direct and effective method for controlling viruses is chemotherapeutics, except for screening of anti-disease species. As the occurrence and harm of plant diseases intensify, production and consumption of pesticides have increased year by year, and greatly contributed to the fertility of agriculture, but also brought a series of problems, such as the increase of drug resistance of plant pathogens and the excessive pesticide residues. In recent years, biopesticide, as characterized by environmentally safe due to low residual, safe to non-target organism due to better specificity and not as susceptible to produce drug resistance due to diverse work ways, has gained more attention than ever before and exhibited great development potential. Now much progress has been made about researches on new biogenic anti-plant-virus substances. The types of active components include proteins, polysaccharides and small molecules (alkaloids, flavonoids, phenols, essential oils) from plants, proteins and polysaccharides from microorganisms, polysaccharides from algae and oligochitosan from animals. This study summarized the research advance of biogenic anti-plant-virus substances in recent years and put forward their further development in the future.

Antiviral activity of glycoprotein GP-1 isolated from Streptomyces kanasensis ZX01

Plant virus diseases have seriously damaged global food security. However, current antiviral agents are not efficient enough for the requirement of agriculture production. So, developing new efficient and nontoxic antiviral agents is imperative. GP-1, from Streptomyces kanasensis ZX01, is a new antiviral glycoprotein, of which the antiviral activity and the mode of action against Tobacco mosaic virus (TMV) were investigated in this study. The results showed that GP-1 could fracture TMV particles, and the infection and accumulation of TMV in host plants were inhibited. Moreover, GP-1 could induce systematic resistance against TMV in the host, according to the results of activities of defensive enzymes increasing, MDA decreasing and overexpression of pathogenesis-related proteins. Furthermore, GP-1 could promote growth of the host plant. In conclusion, GP-1 showed the ability to be developed as an efficient antiviral agent and a fertilizer for agriculture.

Streptomyces kanasensis sp. nov., an Antiviral Glycoprotein Producing Actinomycete Isolated from Forest Soil Around Kanas Lake of China

A filamentous actinomycete, designated strain ZX01(T), was isolated from forest soil around Kanas Lake of China. A polyphasic taxonomic study was carried out to establish the status of strain ZX01(T). Chemical and morphological properties of the isolate were similar to those of species of the genus Streptomyces. Analysis of the almost complete 16S rRNA gene sequence placed strain ZX01(T) in the genus Streptomyces where it formed a distinct phyletic line with recognized species of this genus. The strain exhibited the highest sequence similarities to Streptomyces lavendofoliae NBRC 12882(T) (99.1%), S. luridus NBRC 12793(T) (99.0%), S. lavendulocolor NBRC 12881(T) (99.0%), S. gobitricini NBRC 15419(T) (99.0%), and S. roseolilacinus NBRC 12815(T) (98.9%). Low DNA-DNA relatedness values of 54.0, 50.0, 60.0, 66.7, and 50.4%, respectively, were found between strain ZX01(T) and corresponding strains above. A number of phenotypic properties also enabled the isolate to be differentiated from related species of the genus Streptomyces. Therefore, it is proposed that strain ZX01(T) should be classified as the type strain of a novel species in the genus Streptomyces, Streptomyces kanasensis sp. nov. The type strain is ZX01(T) (= CGMCC 4893(T) =JCM 30232(T)).