Sclerotium rolfsii lectin induces opposite effects on normal PBMCs and leukemic Molt-4 cells by recognising TF antigen and its variants as receptors

Purification and characterization of lectin from Phyllanthus reticulatus (PRL) plant fruit inducing cytotoxic effect on T47D and SKBR3 breast cancer cell lines

Lectins are a heterogeneous group of carbohydrate-binding proteins that vary in size, structure, molecular organization, and binding patterns. They evoke diverse biological responses by specifically binding to cell surface glycans and function as recognition molecules. In this study, a lectin from the fruit of Phyllanthus reticulatus was purified using mucin-affinity chromatography. The Phyllanthus reticulatus lectin (PRL) is non-specific to blood groups, with its hemagglutination activity strongly inhibited by asialo-mucin and weakly inhibited by mucin, fetuin, asialo-fetuin, and ovalbumin. The purified PRL exists in a monomeric form and has an estimated molecular weight of approximately 36 kDa (as determined by SDS-PAGE) and 35.07 kDa (as determined by ESI-Q-TOF-MS/MALDI-TOF-MS). The hemagglutination activity of PRL remains stable at an acidic pH of 4.2 and at temperatures up to 60 °C. Glycan array analysis revealed a fine sugar specificity towards fucose and fucose-containing complex glycans. Notably, PRL exhibited a dose-dependent cytotoxic effect on T47D and SKBR3 breast cancer cell lines by inducing apoptosis, as assessed through MTT assay and annexin V/PI staining. These results suggest that PRL is a novel plant lectin with strong apoptotic effects on breast cancer cell lines and distinct carbohydrate specificity, highlighting its potential significance in cancer glycobiology.

Combination of atmospheric and room temperature plasma and ribosome engineering techniques to enhance the antifungal activity of Bacillus megaterium L2 against Sclerotium rolfsii

BACKGROUND

Sclerotium rolfsii is an extremely destructive phytopathogenic fungus that causes significant economic losses. Biocontrol strategies utilizing antagonistic microorganisms present a promising alternative for controlling plant pathogens. Bacillus megaterium L2 has been identified as a potential microbial biocontrol agent in our previous study; however, its efficacy in controlling pathogens has yet to meet current demands. This study aims to enhance the antifungal activity of strain L2 against S. rolfsii R-67 through a two-round mutagenesis strategy and to preliminarily investigate the mutagenesis mechanism of the high antifungal activity mutant.

RESULTS

We obtained mutant Dr-77 with the strongest antifungal activity against R-67, and its cell-free supernatant significantly reduced the infection potential of R-67 to Amorphophallus konjac corms, which may be attributed to the antimicrobial compound phenylacetic acid (PAA), and PAA content in Dr-77 (5.78 mg/mL) was 28.90 times higher than original strain L2. This compound exhibited strong antifungal ability against R-67, with a half maximal effective concentration (EC50) value of 0.475 mg/mL, significantly inhibiting mycelial growth and destroying the ultrastructure of R-67 at EC50 value. Notably, PAA also exhibited broad-spectrum antifungal activity against six phytopathogens at EC50 value. Moreover, genome analysis revealed nine different gene mutations, including those involved in PAA biosynthesis, and the activities of prephenate dehydratase (PheA) and phenylacetaldehyde dehydrogenase (ALDH) in PAA biosynthesis pathway were significantly increased.

CONCLUSION

These results suggest that the elevated PAA content is a primary factor contributing to the enhanced antifungal activity of Dr-77, and that this mutagenesis strategy offers valuable guidance for the breeding of functional microbial resources. © 2024 Society of Chemical Industry.

Lectin-glycan interactions: a comprehensive cataloguing of cancer-associated glycans for biorecognition and bio-alteration: a review

This comprehensive review meticulously compiles data on an array of lectins and their interactions with different cancer types through specific glycans. Crucially, it establishes the link between aberrant glycosylation and cancer types. This repository of lectin-defined glycan signatures, assumes paramount importance in the realm of cancer and its dynamic nature. Cancer, known for its remarkable heterogeneity and individualized behaviour, can be better understood through these glycan signatures. The current review discusses the important lectins and their carbohydrate specificities, especially recognizing glycans of cancer origin. The review also addresses the key aspects of differentially expressed glycans on normal and cancerous cell surfaces. Specific cancer types highlighted in this review include breast cancer, colon cancer, glioblastoma, cervical cancer, lung cancer, liver cancer, and leukaemia. The glycan profiles unveiled through this review hold the key to tailor-made treatment and precise diagnostics. It opens up avenues to explore the potential of targeting glycosyltransferases and glycosidases linked with cancer advancement and metastasis. Armed with knowledge about specific glycan expressions, researchers can design targeted therapies to modulate glycan profiles, potentially hampering the advance of this relentless disease.

Transcriptomics and Metabolomics Analysis of Sclerotium rolfsii Fermented with Differential Carbon Sources

Scleroglucan is obtained from Sclerotium rolfsii and is widely used in many fields. In this study, transcriptomics combined with metabolomics were used to study the global metabolites and gene changes. The results of the joint analysis showed that the DEGs (differentially expressed genes) and DEMs (differentially expressed metabolites) of SEPS_48 (fermented with sucrose as a carbon source for 48 h) and GEPS_48 (fermented with glucose as a carbon source for 48 h) comparison groups were mainly related to cell metabolism, focusing on carbohydrate metabolism, amino acid metabolism, and amino sugar and nucleoside sugar metabolism. We therefore hypothesized that the significant differences in these metabolic processes were responsible for the differences in properties. Moreover, the joint analysis provides a scientific theoretical basis for fungal polysaccharides biosynthesis and provides new insights into the effects of carbon sources on the production. As an excellent bioenergy and biological product, scleroglucan can be better applied in different fields, such as the food industry.

Purification and characterisation of a xylose-specific mitogenic lectin from Fusarium sambucinum

A xylose-specific intracellular lectin, showing hemagglutination only with rabbit erythrocytes was purified from mycelium of Fusarium sambucinum which was designated as FSL. An array of anion exchange chromatography on Q-Sepharose and gel-exclusion chromatography on Sephadex G-100 resulted in 84.21% yield and 53.99-fold purification of lectin with specific activity of 169.53 titre/mg. Molecular weight of FSL determined by SDS-PAGE was 70.7 kDa, which was further confirmed by gel-exclusion chromatography. Native-PAGE analysis of FSL showed its monomeric nature. FSL was observed to be a glycoprotein containing 2.9% carbohydrate. Hapten inhibition profile of FSL displayed its strong affinity towards D-xylose (MIC 1.562 mM), L-fucose (MIC 6.25 mM), D-mannose (MIC 3.125 mM), fetuin (MIC 15.62 μg/mL), asialofetuin (MIC 125 μg/mL) and BSM (MIC 3.125 μg/mL). Affinity of FSL towards xylose is rare. FSL was found stable over a pH range 6.0-7.5 and upto 40 °C temperature. Hemagglutination activity of FSL remained unaffected by divalent ions. Lectin concentration of 5 μg/mL was found sufficient to stimulate proliferation of murine spleen cells and its concentration 75 μg/mL exhibited highest mitogenic potential. FSL exhibited maximum mitogenic stimulatory index of 14.35. The purification, characterisation and mitogenicity of F. sambucinum lectin has been reported first time.