Purification of chrysancorin, a novel antifungal protein with mitogenic activity from garland chrysanthemum seeds

Dual Antifungal and Antiproliferative Activities of a Novel Protein Fraction from a Medicinally Important Herb Trillium govanianum Wall. ex. D. Don

Antimicrobial resistance of microorganisms and the unwanted side effects of chemoradiation therapy in cancer are major issues in healthcare. In recent times, protein-based drugs have emerged as promising candidates due to their high specificity, less side effects, etc. In this context, the rhizome of Trillium govanianum was first explored for biologically active proteins/peptides. For this, three protein fractions namely Aqueous protein fraction (APF), Hexane-Methanol-treated aqueous protein fraction (HMAPF), and Methanol-treated aqueous protein fraction (MAPF) were prepared and evaluated for antimicrobial and antiproliferative activities. In antifungal activity, HMAPF showed the lowest MIC90 values of 1.56 µg/ml against Candida parapsilosis and Candida glabrata and 3.12 µg/ml against Candida albicans and Candida auris. The antifungal activity was further confirmed by a chitinase assay, a growth kinetics and a proteinase inhibitory assay. Surprisingly, none of the three protein fractions exhibited antibacterial activity against Escherichia coli and Staphylococcus aureus. Moreover, APF exhibited potent antiproliferative and antioxidant activities with IC50 values of 18 µg/ml and 227 µg /ml, respectively. For HMAPF, an IC50 value of 70 µg/ml against the MDA-MB-231 cell line was observed. The present results demonstrate that the protein fractions, particularly HMAPF and APF, might serve as potential sources of a dual antifungal and antiproliferative protein-based drug.

The Updated Review on Plant Peptides and Their Applications in Human Health

Biologically active plant peptides, consisting of secondary metabolites, are compounds (amino acids) utilized by plants in their defense arsenal. Enzymatic processes and metabolic pathways secrete these plant peptides. They are also known for their medicinal value and have been incorporated in therapeutics of major human diseases. Nevertheless, its limitations (low bioavailability, high cytotoxicity, poor absorption, low abundance, improper metabolism, etc.) have demanded a need to explore further and discover other new plant compounds that overcome these limitations. Keeping this in mind, therapeutic plant proteins can be excellent remedial substitutes for bodily affliction. A multitude of these peptides demonstrates anti-carcinogenic, anti-microbial, anti-HIV, and neuro-regulating properties. This article's main aim is to list out and report the status of various therapeutic plant peptides and their prospective status as peptide-based drugs for multiple diseases (infectious and non-infectious). The feasibility of these compounds in the imminent future has also been discussed.

Therapeutic Potential of Medicinal Plant Proteins: Present Status and Future Perspectives

Biologically active molecules obtained from plant sources, mostly including secondary metabolites, have been considered to be of immense value with respect to the treatment of various human diseases. However, some inevitable limitations associated with these secondary metabolites like high cytotoxicity, low bioavailability, poor absorption, low abundance, improper metabolism, etc., have forced the scientific community to explore medicinal plants for alternate biologically active molecules. In this context, therapeutically active proteins/peptides from medicinal plants have been promoted as a promising therapeutic intervention for various human diseases. A large number of proteins isolated from the medicinal plants have been shown to exhibit anti-microbial, anti-oxidant, anti-HIV, anticancerous, ribosome-inactivating and neuro-modulatory activities. Moreover, with advanced technological developments in the medicinal plant research, medicinal plant proteins such as Bowman-Birk protease inhibitor and Mistletoe Lectin-I are presently under clinical trials against prostate cancer, oral carcinomas and malignant melanoma. Despite these developments and proteins being potential drug candidates, to date, not a single systematic review article has documented the therapeutical potential of the available biologically active medicinal plant proteome. The present article was therefore designed to describe the current status of the therapeutically active medicinal plant proteins/peptides vis-à-vis their potential as future protein-based drugs for various human diseases. Future insights in this direction have also been highlighted.

Structure-Activity-Relationship and Mechanistic Insights for Anti-HIV Natural Products

Acquired Immunodeficiency Syndrome (AIDS), which chiefly originatesfroma retrovirus named Human Immunodeficiency Virus (HIV), has impacted about 70 million people worldwide. Even though several advances have been made in the field of antiretroviral combination therapy, HIV is still responsible for a considerable number of deaths in Africa. The current antiretroviral therapies have achieved success in providing instant HIV suppression but with countless undesirable adverse effects. Presently, the biodiversity of the plant kingdom is being explored by several researchers for the discovery of potent anti-HIV drugs with different mechanisms of action. The primary challenge is to afford a treatment that is free from any sort of risk of drug resistance and serious side effects. Hence, there is a strong demand to evaluate drugs derived from plants as well as their derivatives. Several plants, such as Andrographis paniculata, Dioscorea bulbifera, Aegle marmelos, Wistaria floribunda, Lindera chunii, Xanthoceras sorbifolia and others have displayed significant anti-HIV activity. Here, weattempt to summarize the main results, which focus on the structures of most potent plant-based natural products having anti-HIV activity along with their mechanisms of action and IC50 values, structure-activity-relationships and important key findings.

Plant antifungal proteins and their applications in agriculture

Fungi are far more complex organisms than viruses or bacteria and can develop numerous diseases in plants that cause loss of a substantial portion of the crop every year. Plants have developed various mechanisms to defend themselves against these fungi which include the production of low-molecular-weight secondary metabolites and proteins and peptides with antifungal activity. In this review, families of plant antifungal proteins (AFPs) including defensins, lectins, and several others will be summarized. Moreover, the application of AFPs in agriculture will also be analyzed.

Ten challenges on Cryptococcus and cryptococcosis

Cryptococcosis has become a significant public global health problem worldwide. Caused by two species, Cryptococcus neoformans or Cryptococcus gattii, this life-threatening infection afflicts not only immunocompromised individuals but also apparently immunocompetent subjects. Hence, cryptococcosis should no longer be considered merely an opportunistic infection. In this article, we focus on ten unanswered questions/topics in this field with the hope to stimulate discussion and research on these topics that would lead not only to a better understanding of the physiopathology of this disease but also to a better diagnosis and prognosis.

Purification and characterization of a rhamnose-binding chinook salmon roe lectin with antiproliferative activity toward tumor cells and nitric oxide-inducing activity toward murine macrophages

In this study, a rhamnose-binding lectin from the roe of chinook salmon (Oncorhynchus tshawytscha) was purified and characterized, and its biological activities were examined in several model systems. Chinook salmon roe lectin had a molecular mass of 30 kDa and agglutinated rabbit and bovine erythrocytes. The hemagglutination activity of the lectin was not affected by metal ions. The lectin was stable up to 70 °C and between pH 4 and pH 11. Chinook salmon roe lectin did not exert antifungal activity toward the fungal species tested and did not exhibit mitogenic response toward mouse splenocytes up to a concentration of 5 mg/mL. The lectin had selective antiproliferative activity toward human breast cancer MCF-7 cells and hepatoma Hep G2 cells. It also induced the production of nitric oxide from mouse peritoneal macrophages. This is the first report that demonstrates these biological activities from chinook salmon roe lectin.

An antifungal defensin from Phaseolus vulgaris cv. 'Cloud Bean'

An antifungal peptide with a defensin-like sequence and exhibiting a molecular mass of 7.3kDa was purified from dried seeds of Phaseolus vulgaris 'Cloud Bean'. The isolation procedure entailed anion exchange chromatography on DEAE-cellulose, affinity chromatography an Affi-gel blue gel, cation exchange chromatography on SP-Sepharose, and gel filtration by fast protein liquid chromatography on Superdex 75. Although the antifungal peptide was unadsorbed on DEAE-cellulose, it was adsorbed on both Affi-gel blue gel and SP-Sepharose. The antifungal peptide exerted antifungal activity against Mycosphaerella arachidicola with an IC(50) value of 1.8 μM. It was also active against Fusarium oxysporum with an IC(50) value of 2.2 μM. It had no inhibitory effect on HIV-1 reverse transcriptase when tested up to 100 μM. Proliferation of L1210 mouse leukemia cells and MBL2 lymphoma cells was inhibited by the antifungal peptide with an IC(50) of 10 μM and 40 μM, respectively.

A relatively stable antifungal peptide from buckwheat seeds with antiproliferative activity toward cancer cells

An antifungal peptide with a molecular mass of approximately 4 kDa was isolated from buckwheat seeds by using ion-exchange chromatography on SP-Sepharose and Q-Sepharose, and gel filtration on Superdex peptide. The peptide was adsorbed on SP-Sepharose in 10 mM NH(4)OAc buffer (pH 4.5) and on Q-Sepharose in 10 mM NH(4)HCO(3) buffer (pH 9.4), and appeared to be highly purified after these two steps. It inhibited mycelial growth in Fusarium oxysporum and Mycosphaerella arachidicola with an IC(50) of 35 and 40 microM, respectively. Its antifungal activity was stable between 0 and 70 degrees C, and between pH 1.0/2.0 and 13. It inhibited proliferation of Hep G2 (hepatoma) cells, L1210 (leukemia) cells, breast cancer (MCF-7) cells, and liver embryonic WRL 68 cells with an IC(50) of 33, 4, 25, and 37 microM, respectively. On the other hand, the peptide was unable to evoke a mitogenic response from splenocytes or induce nitric oxide production by macrophages. It inhibited HIV-1 reverse transcriptase with an IC(50) of 5.5 microM.

A thaumatin-like antifungal protein from the emperor banana

A 20-kDa protein with substantial N-terminal sequence homology to thaumatin-like proteins was isolated from ripe fruits of the emperor banana, Musa basjoo cv. 'emperor banana'. The isolation procedure entailed (NH(4))(2)SO(4) precipitation, ion exchange chromatography on DEAE-cellulose, and affinity chromatography on Affi-gel blue gel. The thaumatin-like protein inhibited mycelial growth in Fusarium oxysporum and Mycosphaerella arachidicola. However, it did not affect the mitogenic response of murine splenocytes or [methyl-(3)H] thymidine incorporation by tumor cells. The activity of HIV-1 reverse transcriptase was slightly inhibited.

An antifungal peptide from red lentil seeds

An antifungal peptide, with a molecular mass of 11 kDa, was isolated from dry seeds of the red lentil (Lens culinaris) using a procedure that involved four chromatographic steps. The antifungal peptide was unadsorbed on DEAE-cellulose, and adsorbed on Affi-gel blue gel and S-Sepharose. The final chromatographic step involved gel filtration by fast protein liquid chromatography on Superdex 75. The antifungal peptide inhibited mycelial growth in Mycosphaerella arachidicola with an IC50 of 36 microM. It also exhibited antifungal activity against Fusarium oxysporum, but there was no inhibitory activity toward tumor cell lines and human immunodeficiency virus type 1 reverse transcriptase (RT).

Isolation and characterization of a novel mung bean protease inhibitor with antipathogenic and anti-proliferative activities

A novel protease inhibitor, designated mungoin, with both antifungal and antibacterial activities, and exhibiting a molecular mass of 10kDa in SDS-polyacrylamide gel electrophoresis, was isolated from mung bean (Phaseolus mungo) seeds. The isolation procedure involved a combination of extraction, ammonium sulfate precipitation, ion exchange chromatography on CM-Sephadex, and high-performance liquid chromatography (HPLC) on SP-Toyopearl. Its isoelectric point was estimated to be 9.8 by isoelectric focusing. Its N-terminal amino acid sequence was determined to be EMPGKPACLDTDDFCYKP, demonstrating some resemblance to the C-terminal sequences of other protease inhibitors and inhibitor precursors from leguminous plants. It exerted a potent inhibitory action toward a variety of fungal species including Physalospora piricola, Mycosphaerella arachidicola, Botrytis cinerea, Pythium aphanidermatum, Sclerotium rolfsii and Fusarium oxysporum, as well as an antibacterial action against Staphylococcus aureus. In addition, this novel plant protease inhibitor displayed anti-proliferative activity toward tumor cells.

A mannose-specific tetrameric lectin with mitogenic and antibacterial activities from the ovary of a teleost, the cobia (Rachycentron canadum)

A tetrameric lectin, with hemagglutinating activity toward rabbit erythrocytes and with specificity toward D-mannosamine and D(+)-mannose, was isolated from the ovaries of a teleost, the cobia Rachycentron canadum. The isolation protocol comprised ion exchange chromatography on CM-cellulose and Q-Sepharose, ion exchange chromatography by fast protein liquid chromatography (FPLC) on Mono Q, and finally gel filtration by FPLC on Superose 12. The lectin was adsorbed on all ion exchangers used. It exhibited a molecular mass of 180 kDa in gel filtration on Superose 12 and a single 45-kDa band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that it is a tetrameric protein. The hemagglutinating activity of the lectin was stable up to 40 degrees C and between pH 4 and pH 10. All hemagglutinating activity disappeared at 60 degrees C and at pH 1 and pH 13. The hemagglutinating activity was doubled in the presence of 0.1 microM FeCl3. The lectin exerted antibacterial activity against Escherichia coli with 50% inhibition at 250 microg. There was no antifungal activity toward Coprinus comatus, Fusarium oxysporum, Mycosphaerella arachidicola, and Rhizoctonia solani at a dose of 300 microg. The lectin exhibited maximal mitogenic response from mouse splenocytes at a concentration of 14 microM.

An antifungal peptide from baby lima bean

A 6-kDa antifungal peptide with inhibitory activity on mycelial growth in Fusarium oxysporum, Mycosphaerella arachidicola, and Physalospora piricola was isolated from baby lima beans. The peptide suppressed growth in M. arachidicola with an IC(50) of 0.87 muM and inhibited activity of HIV-1 reverse transcriptase with an IC(50) of 4 muM. The peptide exhibited an N-terminal amino acid sequence similar to those of leguminous defensins. The isolation procedure comprised ion exchange chromatography on diethylaminoethyl (DEAE)-cellulose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography on carboxymethyl (CM)-cellulose, and gel filtration by fast protein liquid chromatography on Superdex 75. The peptide was unadsorbed on DEAE-cellulose and Affi-gel blue gel but was adsorbed on CM-cellulose.

An antifungal protein from the pea Pisum sativum var. arvense Poir

An antifungal protein with a molecular mass of 11 kDa and a lysine-rich N-terminal sequence was isolated from the seeds of the pea Pisum sativum var. arvense Poir. The antifungal protein was unadsorbed on DEAE-cellulose but adsorbed on Affi-gel blue gel and CM-cellulose. It exerted antifungal activity against Physalospora piricola with an IC50 of 0.62 microM, and also antifungal activity against Fusarium oxysporum and Mycosphaerella arachidicola. It inhibited human immunodeficiency virus type 1 reverse transcriptase with an IC50 of 4.7 microM.

A lectin with some unique characteristics from the samta tomato

A lectin, with a molecular mass of 79 kDa, and with specificity toward rhamnose and O-nitrophenyl-beta-D-galactopyranoside, was isolated from samta tomato fruits. The procedure entailed ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography on CM-cellulose and gel filtration by fast protein liquid chromatography on Superdex 75. The lectin was unadsorbed on DEAE-cellulose but adsorbed on Affi-gel blue gel and CM-cellulose. The lectin was stable up to 70 degrees C. The lectin activity was potentiated by NaOH solutions (25-100 mM), but was reduced by 50 and 100 mM HCl solutions. The activity of the lectin was reduced in the presence of CaCl(2), MgCl(2) and ZnCl(2), but was potentiated by 5 and 10 mM AlCl(3) solutions. The lectin stimulated the mitogenic response in mouse splenocytes and inhibited human immunodeficiency virus-1 reverse transcriptase with an IC(50) of 6.2 microM.

Ganodermin, an antifungal protein from fruiting bodies of the medicinal mushroom Ganoderma lucidum

A 15-kDa antifungal protein, designated ganodermin, was isolated from the medical mushroom Ganoderma lucidum. The isolation procedure utilized chromatography on DEAE-cellulose, Affi-gel blue gel, CM-Sepharose and Superdex 75. Ganodermin was unadsorbed on DEAE-cellulose and adsorbed on Affi-gel blue gel and CM-Sepharose. Ganodermin inhibited the mycelial growth of Botrytis cinerea, Fusarium oxysporum and Physalospora piricola with an IC50 value of 15.2 microM, 12.4 microM and 18.1 microM, respectively. It was devoid of hemagglutinating, deoxyribonuclease, ribonuclease and protease inhibitory activities.

An antifungal protein from flageolet beans

A protein with antifungal and hemagglutinating activities was isolated from dried flageolet beans (Phaseolus vulgaris cv. 'Flageolet Bean'). The protein was unadsorbed on DEAE-cellulose but adsorbed on Affi-gel blue gel and CM-cellulose. The protein demonstrated antifungal activity against Mycophaerella arachidicola with an IC50 of 9.8 microM, but was inactive toward Fusarium oxysporum and Botrytis cinerea. Its hemagglutinating activity could not be inhibited by a variety of the sugars tested. The activity was stable up to 60 degrees C. At 70 degrees C, 75% of the hemagglutinating activity remained while no activity was discernible at and above 100 degrees C. The hemagglutinating activity was stable in the presence of a variety of monovalent, divalent and trivalent chlorides, and also when the ambient pH changed from 3 to 12. It did not exert any mitogenic activity on mouse splenocytes in vitro. Neither did it inhibit HIV-1 reverse transcriptase. It inhibited [3H-methyl]-thymidine incorporation into leukemia L1210 cells with an IC50 of about 4 microM.

An antifungal peptide from the coconut

A chromatographic procedure consisting of ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography on CM-cellulose, and gel filtration by fast performance liquid chromatography on Supedex 75 was utilized to isolate a 10 kDa antifungal peptide from coconut flesh. The peptide was unadsorbed on DEAE-cellulose, but adsorbed on Affi-gel blue gel and CM-cellulose. It displayed antifungal activity against Fusarium oxysporum, Mycosphaerella arachidicola and Physalospora piricola. The IC50 values of its inhibitory activities on mycelial growth in M. arachidicola and HIV-1 reverse transcriptase activity were respectively 1.2 and 52.5 microM.

Naturally derived anti-HIV agents

The urgent need for new anti-HIV/AIDS drugs is a global concern. In addition to obvious economical and commercial hurdles, HIV/AIDS patients are faced with multifarious difficulties associated with the currently approved anti-HIV drugs. Adverse effects, the emergence of drug resistance and the narrow spectrum of activity have limited the therapeutic usefulness of the various reverse transcriptase and protease inhibitors that are currently available on the market. This has driven many scientists to look for new anti-retrovirals with better efficacy, safety and affordability. As has always been the case in the search for cures, natural sources offer great promise. Several natural products, mostly of plant origin have been shown to possess promising activities that could assist in the prevention and/or amelioration of the disease. Many of these anti-HIV agents have other medicinal values as well, which afford them further prospective as novel leads for the development of new drugs that can deal with both the virus and the various disorders that characterize HIV/AIDS. The aim of this review is to report new discoveries and updates pertaining to anti-HIV natural products. In the review anti-HIV agents have been classified according to their chemical classes rather than their target in the HIV replicative cycle, which is the most frequently encountered approach. Perusal of the literature revealed that most of these promising naturally derived anti-HIV compounds are flavonoids, coumarins, terpenoids, alkaloids, polyphenols, polysaccharides or proteins. It is our strong conviction that the results and experiences with many of the anti-HIV natural products will inspire and motivate even more researchers to look for new leads from plants and other natural sources.

Pleurostrin, an antifungal peptide from the oyster mushroom

A 7kDa peptide, with inhibitory activity on mycelial growth in the fungi Fusaerium oxysporum, Mycosphaerella arachidicola and Physalospora piricola, was isolated from fresh fruiting bodies of the oyster mushroom. The isolation procedure entailed extraction with an aqueous buffer, ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel and gel filtration by fast protein liquid chromatography on Superdex 75. The protein was unadsorbed on DEAE-cellulose and adsorbed on Affi-gel blue gel. It demonstrated an N-terminal sequence different from known antifungal proteins and peptides.

An antifungal protein from ginger rhizomes

There are very few reports on antifungal proteins from rhizomes and there is none from the family of Zingiberaceae. An antifungal protein with a novel N-terminal sequence was isolated from ginger rhizomes utilizing a protocol that involved ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, and fast protein liquid chromatography on Superdex 75. The protein was unadsorbed on DEAE-cellulose and adsorbed on Affi-gel blue gel. It exhibited an apparent molecular mass of 32kDa and exerted antifungal activity toward various fungi including Botrytis cinerea, Fusarium oxysporum, Mycosphaerella arachidicola, and Physalospora piricola.

Isolation of trichogin, an antifungal protein from fresh fruiting bodies of the edible mushroom Tricholoma giganteum

An antifungal protein was isolated from the mushroom Tricholoma giganteum var. golden blessings. The protocol included ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography on CM-cellulose, and gel filtration by fast protein liquid chromatography on Superdex 75. The antifungal protein, designated trichogin, was unadsorbed on DEAE-cellulose but was adsorbed on Affi-gel blue gel and CM-cellulose. It exhibited antifungal activity against Fusarium oxysporum, Mycosphaerella arachidicola and Physalospora piricola. Trichogin inhibited HIV-1 reverse transcriptase with an IC50 of 83 nM.

Isolation of alliumin, a novel protein with antimicrobial and antiproliferative activities from multiple-cloved garlic bulbs

A protein designated alliumin, with a molecular mass of 13 kDa and an N-terminal sequence similar to a partial sequence of glucanase, and demonstrating antifungal activity against Mycosphaerella arachidicola, but not against Fusarium oxysporum, was isolated from multiple-cloved garlic (Allium sativum) bulbs. The protein, designated as alliumin, was purified using ion exchange chromatography on DEAE-cellulose, CM-cellulose and Mono S, affinity chromatography on Affi-gel blue gel, and gel filtration on Superdex 75. Alliumin was unadsorbed on DEAE-cellulose, but was adsorbed on Affi-gel blue gel, CM-cellulose and Mono S. Its antifungal activity was retained after boiling for 1 h and also after treatment with trypsin or chymotrypsin (1:1, w/w) for 30 min at room temperature. Alliumin was inhibitory to the bacterium Pseudomonas fluorescens and exerted antiproliferative activity toward leukemia L1210 cells. However, it was devoid of ribonuclease activity, protease activity, mitogenic activity toward mouse splenocytes, and antiproliferative activity toward hepatoma Hep G2 cells.

Purification and characterization of a chitinase-like antifungal protein from black turtle bean with stimulatory effect on nitric oxide production by macrophages

An antifungal protein was isolated from black turtle bean, Phaseolus vulgaris cv. "Black Turtle". The purified protein displayed an N-terminal amino acid sequence with 60-80% homology to chitinases. The isolated protein specifically inhibited two species of fungi, namely Fusarium oxysporum and Mycosphaerella arachidicola , among several phytopathogenic fungi tested. Its antifungal activity was retained after incubation at 60 degrees C for 15 minutes, diminished after exposure to 80 degrees C, and was completely abrogated after treatment at 100 degrees C. The antifungal protein had higher thermostability than the antifungal protein mollisin from chestnut. It stimulated nitric oxide production by murine peritoneal macrophages, but exerted neither mitogenic nor cytotoxic activity on murine splenocytes, activities that may be related to allergic responses.

First report of a glutamine-rich antifungal peptide with immunomodulatory and antiproliferative activities from family Amaryllidaceae

This represents the first report of purification of a glutamine-rich antifungal peptide from family Amarylliaceace. The peptide, designated as nartazin, was purified from the bulbs of the Chinese daffodil Narcissus tazetta var. chinensis by means of ion-exchange chromatography and affinity chromatography. Its molecular mass was 7.1kDa, as determined by SDS-PAGE and gel filtration. Nartazin stimulated proliferation of mouse splenocytes and bone marrow cells but inhibited proliferation of leukemia L1210 cells. It also inhibited translation in a cell-free rabbit reticulocyte lysate system. The sequence of its first 20 N-terminal residues was characterized by an abundance of glutamine. The peptide possessed antifungal activity on four phytopathogenic fungi. Its activity was retained after incubation with bovine trypsin and chymotrypsin (enzyme: substrate ratio 1:10 w/w) at 37 degrees C for 1h but was attenuated after treatment with proteinase K. The data revealed its pronounced resistance to proteolytic digestion.

Actinchinin, a novel antifungal protein from the gold kiwi fruit

An antifungal protein designated actinchinin, with an N-terminal sequence different from that of the thaumatin-like antifungal protein from green kiwi fruit, was isolated from the gold kiwi fruit. The antifungal protein, unlike its counterpart from green kiwi fruit, did not exert antifungal activity against Botrytis cinerea, but was active against Fusarium oxysporum which was unresponsive to thaumatin-like protein from green kiwi fruit. Actinchinin was isolated using a protocol that comprised ion exchange chromatography on CM-cellulose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography by fast protein liquid chromatography (FPLC) on Mono S, and gel filtration by FPLC on Superdex 75. Actinchinin was adsorbed on CM-cellulose, Affi-gel blue gel and Mono S. It was devoid of mitogenic activity toward mouse splenocytes. In contrast to thaumatin-like protein from green kiwi fruit, actinchinin lacked HIV-1 reverse transcriptase inhibiting activity.

Antifungal proteins and peptides of leguminous and non-leguminous origins

Antifungal proteins and peptides, as their names imply, serve a protective function against fungal invasion. They are produced by a multitude of organisms including leguminous flowering plants, non-leguminous flowering plants, gymnosperms, fungi, bacteria, insects and mammals. The intent of the present review is to focus on the structural and functional characteristics of leguminous, as well as non-leguminous, antifungal proteins and peptides. A spectacular diversity of amino acid sequences has been reported. Some of the antifungal proteins and peptides are classified, based on their structures and/or functions, into groups including chitinases, glucanases, thaumatin-like proteins, thionins, and cyclophilin-like proteins. Some of the well-known proteins such as lectins, ribosome inactivating proteins, ribonucleases, deoxyribonucleases, peroxidases, and protease inhibitors exhibit antifungal activity. Different antifungal proteins may demonstrate different fungal specificities. The mechanisms of antifungal action of only some antifungal proteins including thaumatin-like proteins and chitinases have been elucidated.

A napin-like polypeptide from dwarf Chinese white cabbage seeds with translation-inhibitory, trypsin-inhibitory, and antibacterial activities

Napins are 1:1 disulfide-linked complexes of a smaller (ca. 4kDa) subunit and a larger (ca. 10kDa) subunit. The intent of the present study was to ascertain the production of napin by the seeds of a Brassica species that has not been examined previously, and also to explore new biological activities of the napin. A heterodimeric 11-kDa napin-like polypeptide has been isolated from Chinese white cabbage (Brassica chinensis cv dwarf) seeds with a protocol comprising ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, fast protein liquid chromatography (FPLC)-ion exchange chromatography on Mono S and FPLC-gel filtration on Superdex 75. The N-terminal sequence of the 7-kDa subunit manifests striking similarity to napin large chain, albumin and trypsin inhibitor. The N-terminal sequence of the 4-kDa subunit is homologous to napin large chain and an antimicrobial peptide. The napin-like polypeptide inhibited translation in the rabbit reticulocyte system with an IC50 of 18.5nM. This translation-inhibitory activity was stable between pH 4 and 11, and between 10 and 40 degrees C. The polypeptide inhibited trypsin with a higher potency ( IC50 = 8.5 microM) than it inhibited chymotrypsin (IC50 = 220 microM), but was devoid of ribonuclease and antifungal activities. It manifested antibacterial activity against Pseudomonas aeruginosia, Bacillus subtilis, Bacillus cereus, and Bacillus megaterium. The results revealed that the napin-like polypeptide from Chinese white cabbage seeds exhibited some potentially exploitable activities.

A ribonuclease with antimicrobial, antimitogenic and antiproliferative activities from the edible mushroom Pleurotus sajor-caju

A 12 kDa ribonuclease preferential for poly U and with much lower activity toward poly A, poly G and poly C was isolated from fresh fruiting bodies of the mushroom Pleurotus sajor-caju. A purification procedure involving ion exchange chromatography on CM-cellulose, affinity chromatography on Red-Sepharose and Heparin-Sepharose, and fast protein liquid chromatography-gel filtration on Superdex 75 was used. The ribonuclease was adsorbed on all of the first three types of chromatographic media. It exhibited some activity toward herring sperm DNA and calf thymus DNA. The ribonuclease activity was unaffected in the presence of KCl (10 and 100 mM) and NaCl (100 mM and 1 M), but was strongly inhibited by CuSO4 (0.01 and 0.1 mM) and less potently inhibited by other divalent salts including MgCl2, CaCl2, ZnCl2, ZnSO4 and FeSO4. The optimal pH was 5.5 and the ribonuclease was stable up to 60 degrees C for 1 h. The ribonuclease inhibited mycelial growth in the fungi Fusarium oxysporum and Mycosphaerella arachidicola with an IC50 value of 95 and 72 microM, respectively. Out of the 12 species of bacteria tested, only Pseudomonas aeruginosa and Staphylococcus aureus were inhibited in growth by the ribonuclease. Viability of the tumor cells HepG2 (hepatoma) and L1210 (leukemia) was reduced with an IC50 of 0.22 and 0.1 microM, respectively in the presence of the ribonuclease. The ribonuclease inhibited translation in a cell-free rabbit reticulocyte lysate system with an IC50 of 158 nM and 3H-methyl-thymidine uptake by murine splenocytes with an IC50 of 65 nM.

Eryngin, a novel antifungal peptide from fruiting bodies of the edible mushroom Pleurotus eryngii

An antifungal peptide with a molecular mass of 10k Da was isolated from fruiting bodies of the mushroom Pleurotus eryngii. The peptide, designated as eryngin, inhibited mycelial growth in Fusarium oxysporum and Mycosphaerella arachidicola. It was unadsorbed on DEAE-cellulose and adsorbed on Affi-gel blue gel and S-Sepharose. Its N-terminal sequence demonstrated some similarity to the antifungal protein from the mushroom Lyophyllum shimeiji and little resemblance to thaumatin and thaumatin-like proteins.

Purification of glysojanin, an antifungal protein, from the black soybean Glycine soja

A monomeric protein, with a molecular mass of 25 kDa and an N-terminal sequence resembling a segment of chitin synthase, was isolated from the seeds of the black soybean Glycine soja. The protein, designated glysojanin, demonstrated potent antifungal activity against the fungi Fusarium oxysporum and Mycosphaerella arachidicola. It inhibited HIV-1 reverse transcriptase with an IC50 of 47 micromol/L, [methyl-3H]thymidine incorporation by mouse spleen cells with an IC50 of 175 micromol/L, and translation in the rabbit reticulocyte lysate with an IC50 of 20 micromol/L. Glysojanin was purified using a procedure that involved ion-exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, ion-exchange chromatography by fast protein liquid chromatography on Mono S, and gel filtration by fast protein liquid chromatography on Superdex 75.

Lentin, a novel and potent antifungal protein from shitake mushroom with inhibitory effects on activity of human immunodeficiency virus-1 reverse transcriptase and proliferation of leukemia cells

From the fruiting bodies of the edible mushroom Lentinus edodes, a novel protein designated lentin with potent antifungal activity was isolated. Lentin was unadsorbed on DEAE-cellulose, and adsorbed on Affi-gel blue gel and Mono S. The N-terminal sequence of lentin manifested similarity to endoglucanase. Lentin, which had a molecular mass of 27.5 kDa, inhibited mycelial growth in a variety of fungal species including Physalospora piricola, Botrytis cinerea and Mycosphaerella arachidicola. Lentin also exerted an inhibitory activity on HIV-1 reverse transcriptase and proliferation of leukemia cells.

Purification of castamollin, a novel antifungal protein from Chinese chestnuts

A novel antifungal protein, designated castamollin, was isolated from Chinese chestnut (Castanea mollisima) seeds with a procedure involving ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography on CM-Sepharose and FPLC-gel filtration on Superdex 75. Castamollin possessed a novel N-terminal sequence demonstrating little similarity to N-terminal sequences of Castanea sativa chitinase. Castamollin exhibited a molecular mass of 37kDa in gel filtration and SDS-PAGE. It inhibited the activity of human immunodeficiency virus-1 reverse transcriptase with an IC(50) of 7microM and translation in a cell-free rabbit reticulocyte lysate system with an IC(50) of 2.7microM. Castamollin displayed antifungal activity against Botrytis cinerea, Mycosphaerella arachidicola, Physalospora piricola, and Coprinus comatus but was devoid of lectin activity.

The trypsin-inhibitory, immunostimulatory and antiproliferative activities of a napin-like polypeptide from Chinese cabbage seeds

A heterodimeric 13.8 kDa napin-like polypeptide has previously been isolated from Chinese cabbage (Brassica parachinensis) seeds with a procedure involving ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, FPLC-ion exchange chromatography on Mono S and FPLC-gel filtration on Superdex 75. In the present study the N-terminal sequence of the 8.8 kDa subunit of the polypeptide (PQGPQQRPPKLLQQQTNEEHE) was found to have pronounced homology to napins, albumins and trypsin inhibitors, but demonstrated little similarity to the 5 kDa subunit. The polypeptide stimulated nitrite production by mouse peritoneal macrophages and reduced the viability of leukaemia (L1210) cells. It inhibited trypsin with a higher potency than it inhibited chymotrypsin, but was devoid of ribonuclease and antifungal activities.

The immunostimulatory activity and stability of grass carp (Ctenopharyngodon idellus) roe lectin

A hexameric rhamnose-specific lectin with a molecular mass of 205kDa and exhibiting some N-terminal sequence similarity to other fish lectins was isolated from roe of the grass carp (Ctenopharyngodon idellus) by affinity chromatography on rhamnose-Sepharose and ion exchange chromatography by fast protein liquid chromatography on a Mono S column. The lectin exhibited mitogenic activity toward murine splenocytes with a potency lower than that of the plant lectin ConA. It exerted a stimulatory effect at a concentration of 10 micro g/ml on the phagocytic activity of seabream (Sparus sarba) macrophages. It was unstable toward heat (temperature > or =40 degrees C), acid (0.1M HCl), alkali (0.1M NaOH), trypsin and succinylation.

Dendrocin, a distinctive antifungal protein from bamboo shoots

An antifungal protein, with a molecular weight of 20 kDa and an inhibitory action on mycelial growth in the fungi Fusarium oxysporum, Botrytis cincerea, and Mycosphaerella arachidicola, was isolated from fresh bamboo shoots. The protein, designated dendrocin, was unadsorbed on DEAE-cellulose and adsorbed on Affi-gel blue gel and CM-Sepharose. Dendrocin showed only limited similarity in N-terminal sequence to thaumatin-like proteins, unlike other thaumatin-like proteins which closely resemble each other. Its molecular weight was also lower than those of the previously reported thaumatin-like proteins. The protein was devoid of hemagglutinating and ribonuclease activities found in some antifungal proteins.

Isolation of a napin-like polypeptide with potent translation-inhibitory activity from Chinese cabbage (Brassica parachinensis cv green-stalked) seeds

A heterodimeric napin-like polypeptide was isolated from Brassica parachinensis seeds with a procedure involving ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, FPLC-ion exchange chromatography on Mono S and FPLC-gel filtration on Superdex 75. The N-terminal sequence of the 5 kDa subunit of the polypeptide (PAGPFRIPKKRKKEE) showed high homology with other 2S storage proteins like napins and albumins. The polypeptide potently inhibited translation in a cell free system with an IC50 of 6.2 nM. The translation-inhibiting activity of the polypeptide was relatively stable in the pH range 6-11 and in the temperature range 10-50 degrees C.

Fabin, a novel calcyon-like and glucanase-like protein with mitogenic, antifungal and translation-inhibitory activities from broad beans

A protein with an N-terminal sequence displaying similarities to N-terminal sequences of human calcyon and barley endo-1,4-glucanase, and to C-terminal sequences of human translation initiation factor 4 gamma and yeast superkiller viralicidic activity, was isolated from the broad bean Vicia faba. The protein, termed fabin, has a molecular mass of 34 kDa in SDS-polyacrylamide gel electrophoresis. Antifungal activity of the protein was observed against several fungal species including Rhizoctonia solani, Botrytis cinerea, Fusarium oxysporum and Mycosphaerella arachidicola. Fabin inhibits HIV-1 reverse transcriptase with an IC50 of 34 microM and translation in a rabbit reticulocyte lysate with an IC50 of 2.4 microM. At a concentration of about 1.5 microM fabin is able to elicit a 9-fold increase in the mitogenic response of murine splenocytes.

Cicerarin, a novel antifungal peptide from the green chickpea

A peptide designated cicerarin, with an N-terminal amino acid sequence VKSTGRADDDLAVKTKYLPP dissimilar from known proteins and peptides and a molecular mass of 8kDa, was isolated from seeds of the green chickpea Cicer arietinum cv green chickpea. Cicerarin was isolated with a procedure that involved ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, and gel filtration by fast protein liquid chromatography on Superdex 75. Cicerarin was unadsorbed on DEAE-cellulose and adsorbed on Affi-gel blue gel in 10mM Tris-HCl buffer (pH 7.3). Cicerarin exerted antifungal activity against Botrytis cinerea, Mycosphaerella arachidicola, and Physalospora piricola. The antifungal activity was preserved after exposure to 100 degrees C for 15min.

Alocasin, an anti-fungal protein from rhizomes of the giant taro Alocasia macrorrhiza

An anti-fungal protein designated alocasin was isolated from the rhizomes of the giant taro Alocasia macrorrhiza. The isolation protocol involved ion exchange chromatography on diethylaminoethyl (DEAE)-cellulose, ion exchange chromatography on sulfopropyl (SP)-Sepharose, and gel filtration on Superdex 75. Alocasin, which was unadsorbed on DEAE-cellulose and SP-Sepharose, possessed the N-terminal sequence APEGEV, which exhibited some similarity to that of the miraculin-like anti-fungal protein from Pisum sativum legumes. It demonstrated a molecular mass of 11kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration, and displayed anti-fungal activity against Botrytis cinerea. Alocasin reduced the activity of HIV-1 reverse transcriptase. It exhibited weak hemagglutinating activity, only at a concentration of 1mg/ml.

Isolation of a large thaumatin-like antifungal protein from seeds of the Kweilin chestnut Castanopsis chinensis

A protein with an N-terminal sequence showing a much lesser extent of homology than French bean and kiwi fruit thaumatin-like proteins (TLPs) to other TLPs, and possessing a molecular mass of 30 kDa which is considerably higher than those of previously reported TLPs, has been purified from the seeds of the chestnut Castanopsis chinensis Hance. The protein was unadsorbed on DEAE-cellulose in 10 mM Tris-HCl buffer (pH 7.3), and adsorbed on Affi-gel blue gel in the same buffer, on CM-cellulose in 10 mM ammonium acetate buffer (pH 4.5), and on Mono S in 20 mM ammonium acetate buffer (pH 5.5). A highly purified protein preparation was obtained after fractionation on the first three chromatographic media. Castanopsis TLP appeared as a single band (30 kDa) in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and as a single peak (30 kDa) in gel filtration on Superdex 75 by fast protein liquid chromatography. The TLP exerted antifungal activity against Botrytis cinerea, Fusarium oxysporum, Mycosphaerella arachidicola, and Physalospora piricola, with an IC(50) of 0.5 microM against F. oxysporum. Castanopsis TLP was more potent than French bean and kiwi fruit TLPs in its antifungal activity toward F. oxysporum and M. arachidicola. The antifungal activity of Castanopsis TLP remained essentially unaltered after incubation at 40 degrees C for 10 min, was reduced after incubation at 60 degrees C, and disappeared after treatment at 80 degrees C. The antifungal activity underwent a decline after treatment with trypsin (enzyme:substrate ratio 1:100) at 37 degrees C for 1h but some activity remained. Castanopsis TLP exhibited a much more potent inhibitory activity on HIV-1 reverse transcriptase (IC(50) = 1.6 microM) than kiwi fruit TLP (IC(50) > or = 27 microM). Castanopsis TLP was obtained with a yield of 20 mg from 1 kg chestnut seeds.

A homodimeric sporamin-type trypsin inhibitor with antiproliferative, HIV reverse transcriptase-inhibitory and antifungal activities from wampee (Clausena lansium) seeds

A homodimeric trypsin inhibitor with a molecular mass of 54 kDa was isolated from the seeds of Clausena lansium (Lour) Skeels with a very simple procedure comprising extraction with an aqueous buffer and ion exchange chromatography on CM-cellulose. It inhibited trypsin with an IC50 of 2.2 nM but was without any inhibitory effect on chymotrypsin and proteinase K. The uptake of MTT by human leukemia HL60 and hepatoma Hep G2 cells was inhibited with an IC50 of 100 microM. Translation in the cell-free rabbit reticulocyte lysate system was inhibited with an IC50 of 3.6 microM. The activity of HIV-1 reverse transcriptase was reduced in the presence of the trypsin inhibitor. The trypsin inhibitor exerted antifungal activity toward Physalospora piricola but not Mycosphaerella arachidicola, Botrytis cinerea, Fusarium oxysporum or Coprinus comatus.

Isolation of vulgin, a new antifungal polypeptide with mitogenic activity from the pinto bean

An antifungal polypeptide bearing an N-termnial sequence with some homology to chitinases was purified from an extract of pinto beans. The polypeptide, designated vulgin, exerted antifungal activity toward Mycosphaerella arachidicola, Coprinus cornatus, Fusarium oxysporum and Botrytis cinerea. Vulgin inhibited translation in a rabbit reticulocyte lysate system with an IC50 of 4.3 microM and HIV-1 reverse transcriptase activity with an IC50 of 58 microM. Vulgin stimulated in vitro incorporation of methyl [3H] thymidine into mouse splenocytes.