Mushroom lectins in biomedical research and development

Highlights

• Mushroom lectins of paramount importance in biomedical research are reported.

• Characteristic features of mushroom lectins have been discussed.

• Biomedical applications of mushroom lectins have been elaborated.

Abstract

Lectins are unique biorecognition proteins which recognize and interact with various cell surface carbohydrates/glycoproteins. These ubiquitous molecules are involved in various cell-cell interactions and can be exploited to analyze cell surface associated interactions and biological functions. Amongst fungi, lectins have been extensively explored from mushrooms as compared to microfungi or yeasts. Lectins from basidiomycetes have diverse features in terms of their physico-chemical characteristics and carbohydrate specificity. A plethora of lectins from genera Aleuria, Agrocybe, Boletus, Pleurotus, Russula, Schizophyllum, Volvariella, etc. exhibit potential applications in biomedical field. The current review summarizes the potential sources and characteristics of mushroom lectins. Potential involvement of mushroom lectin as anticancer, mitogenic, antiviral, antimicrobial, antioxidant and therapeutic agents has been discussed.

Introduction

Lectins are quintessential proteins which possess at least one non-catalytic domain [1]. They bind reversibly and specifically to various monosaccharides and oligosaccharides without altering their covalent structure [2]. The distinctive ability of lectins to interact with cell surface glycans and precipitate soluble glycoconjugates leads to agglutination of various cell types. The carbohydrate binding site of lectins interacts with their corresponding glycan structures present on erythrocyte cell surface. Lectins thus have the ability to interact with various glycoconjugates and act as tools in examining cell physiology and pathology [3]. Lectins are ubiquitously distributed in nature and have been reported from plants (monocots, dicots), animals (vertebrates, invertebrates) and various microbes [4]. Microbial lectins from bacteria [5], algae [6], [7], protozoa [8], [9], lichens [10], viruses [11], yeasts [12], basidiomycetes [13], [14] and actinomycetes [15], [16] have been widely characterized and are involved in various cell-cell interactions. Amongst microfungi, lectins have been widely studied from genera Aspergillus [17], [18], [19], [20], [21], Cephalosporium [22], [23], Fusarium [24], [25], [26], Penicillium [27], [28], [29], [30], [31], Rhizoctonia [32], [33], [34] and Sclerotium [35], [36], [37].

Over the years, lectins from diverse sources have been widely explored and an ever increasing body of evidence suggesting that they are involved in various biomedical applications [3], [38], [39], [40], [41], [42], [43]. They are involved in inhibiting cancerous cells through autophagy and apoptosis leading to cell death eventually [44]. By inducing various immune stimulating activities, lectins act as prospective therapeutic agents for treatment of cancer and exhibit clinical significance [45]. Microbial lectins from various sources exhibit potential applications as diagnostic reagents, in bioflocculation, as probiotics and as drug targeting agents [46]. In lieu of various prospective applications of lectins, the current review focuses on up-to-date outline of mushroom lectins pertaining to their diverse sources, characteristics and potential in biomedical research.