Orf239342 from the mushroom Agaricus bisporus is a mannose binding protein

The mannose-binding protein from Agaricus bisporus inhibits the growth of MDA-MB-231 spheroids

A mannose-binding protein from the mushroom Agaricus bisporus (Abmb) inhibits the growth of MDA-MB-231 cells, which is of an aggressive breast cancer subtype. This ability was observed in a monolayer cell (2D) culture setup, which often is unable to capture changes in cell morphology, polarity and division. That shortcoming may overestimate Abmb potency for its development as a pharmaceutical agent and its use in a therapy. Hence, Abmb's inhibition to the cell growth was performed in the 3D cell (spheroid) culture, which is more representative to the situation in vivo. The result showed that, although the presence of Abmb at ~14.7 μM already disrupted the MDA-MB-231 cell morphology in the 2D culture, its presence at ~16.5 μM only ceased the growth of the MDA-MB-231 spheroid. Further, Abmb is unique because structurally it belongs to the R-type lectin (RTL) family; most of mannose-binding protein is of the C-type lectin (CTL). As the natural ligand of Abmb is unknown thus the mechanism of action is unclear, Abmb effect on the cancer cells was assessed via observation of the altered expression of genes involved in the Wnt/β-catenin signalling, which is one of the canonical pathways in the proliferation of cancer cells. The results suggested that Abmb did not alter the pathway upon exerting its anti-proliferative activity to the MDA-MB-231 cells.

New fungal protein from Pleurotus ferulae lanzi induces AMPK-mediated autophagy and G1-phase cell cycle arrest in A549 lung cancer cells

A new protein, designated PFAP, with activity against non-small cell lung cancer (NSCLC), was isolated from Pleurotus ferulae lanzi, a medicinal and edible mushroom. The purification method involved hydrophobic interaction chromatography on a HiTrap Octyl FF column and gel filtration on a Superdex 75 column. Sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) revealed a single band with a molecular weight of 14.68 kDa. Following de novo sequencing and liquid chromatography-tandem mass spectrometry, PFAP was identified as a protein consisting of 135 amino acid residues, with a theoretical molecular weight of 14.81 kDa. Tandem mass tag (TMT)™-based quantitative proteomic analysis and western blotting revealed that AMP-activated protein kinase (AMPK) was significantly upregulated in NSCLC A549 cells, following PFAP treatment. The downstream regulatory factor mammalian target of rapamycin (mTOR) was suppressed, resulting in the activation of autophagy and upregulated expressions of P62, LC3 II/I, and other related proteins. PFAP blocked NSCLC A549 cells in the G1 phase of the cell cycle via upregulating P53 and P21, while subsequently downregulating the expression of cyclin-dependent kinases. PFAP suppresses tumour growth via the same mechanism in a xenograft mouse model in vivo. These results demonstrate that PFAP is a multifunctional protein with anti-NSCLC properties.

Anti-Cancer Potential of Edible/Medicinal Mushrooms in Breast Cancer

Edible/medicinal mushrooms have been traditionally used in Asian countries either in the cuisine or as dietary supplements and nutraceuticals. In recent decades, they have aroused increasing attention in Europe as well, due to their health and nutritional benefits. In particular, among the different pharmacological activities reported (antibacterial, anti-inflammatory, antioxidative, antiviral, immunomodulating, antidiabetic, etc.), edible/medicinal mushrooms have been shown to exert in vitro and in vivo anticancer effects on several kinds of tumors, including breast cancer. In this article, we reviewed mushrooms showing antineoplastic activity again breast cancer cells, especially focusing on the possible bioactive compounds involved and their mechanisms of action. In particular, the following mushrooms have been considered: Agaricus bisporus, Antrodia cinnamomea, Cordyceps sinensis, Cordyceps militaris, Coriolus versicolor, Ganoderma lucidum, Grifola frondosa, Lentinula edodes, and Pleurotus ostreatus. We also report insights into the relationship between dietary consumption of edible mushrooms and breast cancer risk, and the results of clinical studies and meta-analyses focusing on the effects of fungal extracts on breast cancer patients.

Coprinopsis cinerea Galectin CGL1 Induces Apoptosis and Inhibits Tumor Growth in Colorectal Cancer Cells

Mushroom galectins are promising anticancer agents for their low IC50 values against cancer cells in vitro. In this study, two Coprinopsis cinerea galectins, CGL1 and CGL2, were heterologously expressed, and their biochemistry properties and anticancer effects were evaluated. The purified galectins were thermostable at neutral pH conditions. They both existed as tetramers and shared a high affinity towards lactose. CGL1 and CGL2 strongly inhibited the cell viability of many cancer cell lines, including three colorectal cancer cells, in a dose-dependent manner by inducing mitochondria-mediated caspase-dependent apoptosis. Furthermore, CGL1 exhibited higher apoptosis-inducing ability and cytotoxicity than CGL2. In vivo cell viability experiments based on two xenograft mouse models showed that CGL1 had a more substantial inhibitory effect than CGL2 on HCT116 tumor growth (p < 0.0001), whereas only CGL1 inhibited DLD1 tumor growth (p < 0.01). This is the first study to evaluate the anti-colorectal cancer effect of mushroom lectins in vivo, and our results showed that CGL1 is a potent agent for colorectal cancer treatment.

In Vitro Antiviral Activity of Tyrosinase from Mushroom Agaricus bisporus against Hepatitis C Virus

Tyrosinases from a commercial Agaricus bisporus protein extract and directly isolated from white mushrooms were purified in order to obtaining the well-known tyrosinase from A. bisporus (TyrAB) of 45 kDa and a newly discovered 50 kDa tyrosinase isoform (Tyr50 kDa), and tested showing high antiviral activity against the hepatitis C virus for the first time. Cell toxicity and antiviral activity of tyrosinases were determined in cultured Huh 5-2 liver tumor cells transfected with a replicon system (a plasmid that includes all non-structural hepatitis C virus proteins and replicates autonomously). TyrAB was able to inhibit the replication of the hepatitis C virus without inducing toxicity in liver cells. In addition, the post-translational isoform Tyr50 kDa showed higher antiviral capacity than the former (up to 10 times greater), also exhibiting 10 times higher activity than the commercial drug Ribavirin^®. This antiviral activity was directly proportional to the enzymatic activity of tyrosinases, as no antiviral capacity was observed in the inactive form of the enzymes. The tyrosinases approach could represent a new antiviral inhibition mechanism, through a plausible catalytic mechanism of selective hydroxylation of the key role of tyrosine residues in viral proteases.

Man-Specific Lectins from Plants, Fungi, Algae and Cyanobacteria, as Potential Blockers for SARS-CoV, MERS-CoV and SARS-CoV-2 (COVID-19) Coronaviruses: Biomedical Perspectives

Betacoronaviruses, responsible for the “Severe Acute Respiratory Syndrome” (SARS) and the “Middle East Respiratory Syndrome” (MERS), use the spikes protruding from the virion envelope to attach and subsequently infect the host cells. The coronavirus spike (S) proteins contain receptor binding domains (RBD), allowing the specific recognition of either the dipeptidyl peptidase CD23 (MERS-CoV) or the angiotensin-converting enzyme ACE2 (SARS-Cov, SARS-CoV-2) host cell receptors. The heavily glycosylated S protein includes both complex and high-mannose type N-glycans that are well exposed at the surface of the spikes. A detailed analysis of the carbohydrate-binding specificity of mannose-binding lectins from plants, algae, fungi, and bacteria, revealed that, depending on their origin, they preferentially recognize either complex type N-glycans, or high-mannose type N-glycans. Since both complex and high-mannose glycans substantially decorate the S proteins, mannose-specific lectins are potentially useful glycan probes for targeting the SARS-CoV, MERS-CoV, and SARS-CoV-2 virions. Mannose-binding legume lectins, like pea lectin, and monocot mannose-binding lectins, like snowdrop lectin or the algal lectin griffithsin, which specifically recognize complex N-glycans and high-mannose glycans, respectively, are particularly adapted for targeting coronaviruses. The biomedical prospects of targeting coronaviruses with mannose-specific lectins are wide-ranging including detection, immobilization, prevention, and control of coronavirus infection.

Prediction of the Mannose-Binding Site in the Agaricus bisporus Mannose-Binding Protein

Agaricus bisporus mannose-binding protein (Abmb) was discovered as part of mushroom tyrosinase (PPO3) complex. Apart from its presence, nothing is known about its function or activity in the mushroom. The protein is evolutionarily related to lectins with β-trefoil fold, which are glucose or galactose (and their derivatives) binding proteins. Abmb is also recently showed to display the typical agglutination activity of lectin when in complex with PPO3; this further supports Abmb similarity to its structural homologs from lectin with β-trefoil fold. However, Abmb has no affinity towards glucose or galactose but for mannose, thus its binding to the sugar may be different from its homologs. To date, the natural ligand of Abmb is unknown and the structure of Abmb in the presence of a ligand is not available. Therefore, the mannose-binding site of Abmb was predicted using molecular docking, which was consulted with the information from its structural homologs. This conservative approach would prevent over-speculation. The mannose-binding site of Abmb is likely located in the same region to that of Abmb structural homologs but with a shift in position due to the presence of additional surface loop. In addition, benefiting from the information from an in vitro study on Abmb sugar specificity, the mannose poses suggested that the sugar might interact with the side chains of Arg15, Thr45, Gln48, Asp49, Asp51 and Arg51. Most of these residues were equally present in Abmb structural homologs despite variation of their positions in the amino acid sequence. The variation probably originates from alteration of its amino acid sequence during evolution.

Lectins from the Edible Mushroom Agaricus bisporus and Their Therapeutic Potentials

The mushroom Agaricus bisporus secretes biologically active compounds and proteins with benefits for human health. Most reported proteins from A. bisporus are tyrosinases and lectins. Lectins are of therapeutic or pharmaceutical interest. To date, only limited information is available on A. bisporus lectins and lectin-like proteins. No therapeutic products derived from A. bisporus lectin (ABL) are available on the market despite its extensive exploration. Recently, A. bisporus mannose-binding protein (Abmb) was discovered. Its discovery enriches the information and increases the interest in proteins with therapeutic potential from this mushroom. Furthermore, the A. bisporus genome reveals the possible occurrence of other lectins in this mushroom that may also have therapeutic potential. Most of these putative lectins belong to the same lectin groups as ABL and Abmb. Their relationship is discussed. Particular attention is addressed to ABL and Abmb, which have been explored for their potential in medicinal or pharmaceutical applications. ABL and Abmb have anti-proliferative activities toward cancer cells and a stimulatory effect on the immune system. Possible scenarios for their use in therapy and modification are also presented.

Relationship of Agaricus bisporus mannose-binding protein to lectins with β-trefoil fold

Agaricus bisporus mannose-binding protein (Abmb) was discovered as part of the mushroom tyrosinase (PPO3) complex, but its function in the mushroom has remained obscure. The protein has a β-trefoil structure that is common for Ricin-B-like lectins. Indeed, its closest structural homologs are the hemagglutinin components of botulinum toxin (HA-33) and the Ricin-B-like lectin from Clitocybe nebularis (CNL), both of which bind galactose, and actinohivin, a recently discovered mannose-binding lectin from actinomycetes. Here we show that Abmb is evolutionarily related to them, which are lectins with a β-trefoil fold. We also show for the first time that Abmb can exhibit typical lectin agglutination activity but only when in the complex with mushroom tyrosinase. This is unexpected and unique because the two proteins are not evolutionarily related and have different activities. Lectin and tyrosinase major role in defense mechanism as well as Abmb and PPO3 gene regulation during the early stages of the development of mushroom fruiting bodies suggested that Abmb has likely a function in defense against bacterial infection and/or insect-induced damage.

Mushroom extracts and compounds with suppressive action on breast cancer: evidence from studies using cultured cancer cells, tumor-bearing animals, and clinical trials

This article reviews mushrooms with anti-breast cancer activity. The mushrooms covered which are better known include the following: button mushroom Agaricus bisporus, Brazilian mushroom Agaricus blazei, Amauroderma rugosum, stout camphor fungus Antrodia camphorata, Jew's ear (black) fungus or black wood ear fungus Auricularia auricula-judae, reishi mushroom or Lingzhi Ganoderma lucidum, Ganoderma sinense, maitake mushroom or sheep's head mushroom Grifola frondosa, lion's mane mushroom or monkey head mushroom Hericium erinaceum, brown beech mushroom Hypsizigus marmoreus, sulfur polypore mushroom Laetiporus sulphureus, Lentinula edodes (shiitake mushroom), Phellinus linteus (Japanese "meshimakobu," Chinese "song gen," Korean "sanghwang," American "black hoof mushroom"), abalone mushroom Pleurotus abalonus, king oyster mushroom Pleurotus eryngii, oyster mushroom Pleurotus ostreatus, tuckahoe or Fu Ling Poria cocos, and split gill mushroom Schizophyllum commune. Antineoplastic effectiveness in human clinical trials and mechanism of anticancer action have been reported for Antrodia camphorata, Cordyceps sinensis, Coriolus versicolor, Ganoderma lucidum, Grifola frondosa, and Lentinula edodes.

Microwave Hydrodiffusion and Gravity (MHG) Extraction from Different Raw Materials with Cosmetic Applications

Microwave hydrodiffusion and gravity (MHG) and ethanolic solid-liquid extraction were compared using selected plant sources. Their bioactive profile, color features, and proximate chemical characterization were determined. MHG extracts, commercial antioxidants, and three distinct types of thermal spring water were used in a sunscreen cream formulation. Their bioactive capacity, chemical and rheological properties were evaluated. MHG Cytisus scoparius flower extract provided the highest bioactive properties. Pleurotus ostreatus MHG liquor exhibited the highest total solid extraction yield. The Brassica rapa MHG sample stood out for its total protein content and its monosaccharide and oligosaccharide concentration. Quercus robur acorns divided into quarters supplied MHG extract with the lowest energy requirements, highest DPPH inhibition percentage, total lipid content and the highest enzyme inhibition. The chemical and bioactive capacities stability of the sunscreen creams elaborated with the selected MHG extracts and the thermal spring waters showed a similar behavior than the samples containing commercial antioxidants.

Agaricus bisporus mannose binding protein is not an agglutinating protein

Agaricus bisporus mannose binding protein (Abmb) demonstrates permeability to epithelial monolayer barrier of the intestine, resistance to gastrointestinal tract conditions and to proteolysis therefore it holds potential as a drug carrier for oral route administration. Abmb also display antiproliferative activity to breast cancer cells and stimulation of immune system thus could potentially be also developed for therapeutic purpose. It is not immunogenic or toxic thereby safe for use. In this paper we further provide evidence that Abmb also lacks of agglutinating activity despite sharing high structural homology to lectins. Abmb is thereby the only mannose specific binding protein that is not member of lectin family. This evidence provides further support on the use of Abmb as pharmaceutical or medicinal agent. Its molecular globularity that may contribute to its lack of agglutination capacity was also evaluated.