An antifungal peptide from the coconut

The composition, extraction, functional property, quality, and health benefits of coconut protein: A review

Coconut is widely appreciated for its distinctive flavor and is commonly utilized in the production of a variety of goods. Coconut protein, a by-product derived from coconut oil and coconut milk cake, is frequently underutilized or discarded. This study provides a comprehensive overview of the distribution and composition of coconut protein. Analyses reveal that coconut protein, specifically 11S globulin and 7S globulin, is predominantly found in coconut flesh. Furthermore, various extraction techniques for coconut protein, such as chemical, enzymatic, and physical methods, are discussed. The alkali dissolution and acid precipitation methods are widely utilized for extracting coconut protein, with the potential for enhancement through the incorporation of physical methods such as ultrasound. The evaluation of functional properties, quality, and health benefits of coconut protein is essential, given the limitations imposed by its solubility. Modification may be necessary to optimize its functional properties. Coconut presents a promising source of food protein, characterized by balanced amino acid composition, high digestibility, and low allergenic potential. In conclusion, this study provides a comprehensive overview of the extraction methods, functional properties, quality, and nutritional benefits of coconut protein, offering insights for potential future research directions in the field. Additionally, the information presented may serve as a valuable reference for incorporating coconut protein into plant-based food products.

Antimicrobial peptides for novel antiviral strategies in the current post-COVID-19 pandemic

The recent pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has highlighted how urgent and necessary the discovery of new antiviral compounds is for novel therapeutic approaches. Among the various classes of molecules with antiviral activity, antimicrobial peptides (AMPs) of innate immunity are among the most promising ones, mainly due to their different mechanisms of action against viruses and additional biological properties. In this review, the main physicochemical characteristics of AMPs are described, with particular interest toward peptides derived from amphibian skin. Living in aquatic and terrestrial environments, amphibians are one of the richest sources of AMPs with different primary and secondary structures. Besides describing the various antiviral activities of these peptides and the underlying mechanism, this review aims at emphasizing the high potential of these small molecules for the development of new antiviral agents that likely reduce the selection of resistant strains.

Are Herbal-peptides Effective as Adjunctive Therapy in Coronavirus Disease COVID-19?

BACKGROUND

Plant antiviral peptides (AVP) are macromolecules that can inhibit the pathogenesis of viruses by affecting their pathogenic mechanism, but most of these peptides can bind to cell membranes, inhibit viral receptors, and prevent viruses. Recently, due to the coronavirus pandemic, the availability of appropriate drugs with low side effects is needed. In this article, the importance of plant peptides in viral inhibition, especially viral inhibition of the coronavirus family, will be discussed.

METHODS

By searching the databases of PubMed, Scopus, Web of Science, the latest articles on plant peptides effective on the COVID-19 virus were collected and reviewed.

RESULTS

Some proteins can act against the COVID-19 virus by blocking sensitive receptors in COVID-19, such as angiotensin-converting enzyme 2 (ACE2). The 23bp sequence of the ACE2 alpha receptor chain can be considered as a target for therapeutic peptides. Protease and RNAP inhibitors and other important receptors that are active against COVID-19 should also be considered.

CONCLUSION

Herbal medicines with AVP, especially those with a long history of antiviral effects, might be a good choice in complement therapy against the COVID-19 virus.

Plant-Derived Antimicrobial Peptides: Novel Preservatives for the Food Industry

Food spoilage is a widespread issue brought on by the undesired growth of microbes in food products. Thousands of tons of usable food or food products are wasted every day due to rotting in different parts of the world. Several food preservation techniques are employed to prevent food from rotting, including the use of natural or manufactured chemicals or substances; however, the issue persists. One strategy for halting food deterioration is the use of plant-derived antimicrobial peptides (AMPs), which have been investigated for possible bioactivities against a range of human, plant, and food pathogens. The food industry may be able to benefit from the development of synthetic AMPs, produced from plants that have higher bioactivity, better stability, and decreased cytotoxicity as a means of food preservation. In order to exploit plant-derived AMPs in various food preservation techniques, in this review, we also outline the difficulties in developing AMPs for use as commercial food preservatives. Nevertheless, as technology advances, it will soon be possible to fully explore the promise of plant-derived AMPs as food preservatives.

Plant-Derived Antimicrobial Peptides as Potential Antiviral Agents in Systemic Viral Infections

Numerous studies have led to a better understanding of the mechanisms of action of viruses in systemic infections for the development of prevention strategies and very promising antiviral therapies. Viruses still remain one of the main causes of human diseases, mainly because the development of new vaccines is usually challenging and drug resistance has become an increasing concern in recent decades. Therefore, the development of potential antiviral agents remains crucial and is an unmet clinical need. One abundant source of potential therapeutic molecules are plants: they biosynthesize a myriad of compounds, including peptides which can have antimicrobial activity. Our objective is to summarize the literature on peptides with antiviral properties derived from plants and to identify key features of these peptides and their application in systemic viral infections. This literature review highlights studies including clinical trials which demonstrated that plant cyclotides have the ability to inhibit the growth of viruses causing human diseases, defensin-like peptides possess anti-HIV-1 activity, and lipid transfer proteins and some lectins exhibit a varied antimicrobial profile. To conclude, plant peptides remain interesting to explore in the context of emerging and re-emerging infectious diseases.

Isolation and functionalities of bioactive peptides from fruits and vegetables: A reviews

Bioactive peptides have recently gained more research attention as potential therapies for the management of bodily disorders and metabolic syndromes of delicate health importance. On another note, there is a rising trend on a global scale for the consumption and adoption of fruit and vegetables for the fulfilment of dietary and health needs. Furthermore, fruits and vegetables are being more studied as base materials for the isolation of biologically functional components and accordingly, they have been investigated for their concomitant bioactive peptides. This review focuses on isolation and bio-functional properties of bioactive peptides from fruits and vegetables. This manuscript is potential in serving as a material collection for fundamental consultancy on peptides derived from fruits and vegetables, and further canvasses the necessitation for the use of these food materials as primal matter for such.

The Coconut Water Antimicrobial Peptide CnAMP1 Is Taken up into Intestinal Cells but Does Not Alter P-Glycoprotein Expression and Activity

Coconut antimicrobial peptide-1 (CnAMP1) is a naturally occurring bioactive peptide from green coconut water (Cocos nucifera L.). Although biological activities have been reported, the physiological relevance of these reports remains elusive as it is unknown if CnAMP1 is taken up into intestinal cells. To address this open question, we investigated the cytotoxicity of CnAMP1 in intestinal cells and its cellular uptake into human intestinal cells. Considering the importance of the P-glycoprotein (P-gp) to the intestinal metabolism of xenobiotics, we also investigated the influence of CnAMP1 on P-gp activity and expression. Both cell lines showed intracellular fluorescence after incubation with fluorescein labelled CnAMP1, indicating cellular uptake of the intact or fragmented peptide. CnAMP1 (12.5-400 μmol/L) showed no signs of cytotoxicity in LS180 and differentiated Caco-2 cells and did not affect P-gp expression and activity. Further research is required to investigate the identity of CnAMP1 hydrolysis fragments and their potential biological activities.

The use of High-Pressure Processing (HPP) to improve the safety and quality of raw coconut (Cocos nucifera L) water

This research investigated the use of high-pressure processing (HPP) for inactivating vegetative pathogens and spoilage microbiota in fresh unfiltered coconut water (Cocos nucifera L) from nuts obtained from Florida and frozen CW from Brazil with pH >5.0 and storage at 4 °C. Additionally, CW was evaluated to determine if it supported the growth and toxin production of Clostridium botulinum with or without the use of HPP when stored at refrigeration temperatures. Samples of fresh unfiltered CW were inoculated to 5.5 to 6.5 logs/mL with multiple strain cocktails of E. coli O157:H7, Salmonella spp. and Listeria monocytogenes and HPP at 593 MPa for 3 min at 4 °C. HPP and inoculated non-HPP controls were stored at 4 °C for 54 and 75 days for Florida CW and Brazil CW, respectively. Results of analyses showed HPP samples with <1 CFU/mL and no detection (negative/25 mL) with enrichment procedures for the 3 inoculated pathogens for all analyses. The non-HPP control samples did not show growth of the pathogens but a gradual decrease in levels to ca. 3-Logs/mL by day 54 in the fresh Florida CW and similarly in frozen Brazil CW by Day 75. Microbial spoilage of uninoculated samples was evaluated for normal spoilage microbiota through 120 days storage at 4 °C. Microbial counts remained at ca. 2-logs with no detectable signs of spoilage for HPP samples through 120 d. The non-HPP control samples spoiled within 2 weeks of storage at 4 °C with gas production, cloudiness, and off-odors. To evaluate if CW supports the growth and toxin production of C. botulinum, samples of unfiltered and filtered (0.2 μm) CW were inoculated with either proteolytic or non-proteolytic C. botulinum spores at 2 log CFU/mL that were processed at 593 MPa for 3 min and stored at 4 °C and 10 °C for 45 days. Inoculated positive and non-inoculated negative controls were prepared and stored as the HPP treated and non-HPP samples. No growth of C. botulinum or toxin production was detected in either the unfiltered or filtered CW regardless if products were HPP treated or not. All inoculated samples with C. botulinum spores were enriched at Day-45 in PYGS media to determine the viability of the inoculated spores at the end of shelf-life and screened for C. botulinum toxins. In all samples, C. botulinum toxin Types A, B and E were detected indicating spores were viable throughout the storage. Type F toxin was not detected possibly due to inherent conditions in the samples that may affected toxin screening.

Development and validation of a rapid reversed-phase liquid chromatography method for CnAMP1 peptide quantification in human intestinal cell lines

Plant foods are rich sources of biologically active peptides that may have a role in the prevention of diseases. Coconut water is a valuable beverage due to its nutrient composition and the presence of bioactive compounds, such as the peptide CnAMP1. It is unknown if CnAMP1 can be absorbed into intestinal cells. We, therefore, aimed to develop and validate a simple reversed-phase liquid chromatographic method to quantify the peptide in Caco-2 and LS180 cell lysates. CnAMP1 standards (1-200 µmol/L) and spiked cell lysates were injected onto a Reprosil-Pur 120 C18-AQ column (4.6 × 250 mm) using acetonitrile:water:trifluoroacetic acid (14.0:85.9:0.1, by volume) as mobile phase in isocratic mode at flow rate of 1 mL/min. The method achieved rapid separation (total run time of 6 min), with linear response, good sensitivity (limit of detection, 8.2 ng; lower limit of quantification, 30.6 ng) and no interfering peaks. Best recoveries (84-96%), accuracies (7.6-14.8%) and precision (1.5-8%) were found for LS180 cell lysates spiked with medium (50 µmol/L) and high (100 µmol/L) amounts of the peptide. Uptake assays detected no peptides in the cell lysates; however, after the first 15-min incubation CnAMP1 underwent partial hydrolysis upon incubation with LS180 cells (29%) and extensive hydrolysis with Caco-2 cells (93%).

Antimicrobial Peptides from Fruits and Their Potential Use as Biotechnological Tools-A Review and Outlook

Bacterial resistance is a major threat to plant crops, animals and human health, and over the years this situation has increasingly spread worldwide. Due to their many bioactive compounds, plants are promising sources of antimicrobial compounds that can potentially be used in the treatment of infections caused by microorganisms. As well as stem, flowers and leaves, fruits have an efficient defense mechanism against pests and pathogens, besides presenting nutritional and functional properties due to their multifunctional molecules. Among such compounds, the antimicrobial peptides (AMPs) feature different antimicrobials that are capable of disrupting the microbial membrane and of acting in binding to intra-cytoplasmic targets of microorganisms. They are therefore capable of controlling or halting the growth of microorganisms. In summary, this review describes the major classes of AMPs found in fruits, their possible use as biotechnological tools and prospects for the pharmaceutical industry and agribusiness.

Purification, characterization, synthesis, in vivo and in vitro antihypertensive activity of bioactive peptides derived from coconut (Cocos nucifera L.) cake globulin hydrolysates

This paper reports the purification, characterization,in vivoandin vitroantihypertensive activity of two novel peptides derived from coconut cake globulin hydrolysates.

Purification, characterization and synthesis of antioxidant peptides from enzymatic hydrolysates of coconut (Cocos nucifera L.) cake protein isolates

Two antioxidant peptides were isolated, characterized, identified and synthesized from enzymatic hydrolysates of coconut cake protein isolates in this paper.

Mining Novel Allergens from Coconut Pollen Employing Manual De Novo Sequencing and Homology-Driven Proteomics

Coconut pollen, one of the major palm pollen grains is an important constituent among vectors of inhalant allergens in India and a major sensitizer for respiratory allergy in susceptible patients. To gain insight into its allergenic components, pollen proteins were analyzed by two-dimensional electrophoresis, immunoblotted with coconut pollen sensitive patient sera, followed by mass spectrometry of IgE reactive proteins. Coconut being largely unsequenced, a proteomic workflow has been devised that combines the conventional database-dependent analysis of tandem mass spectral data and manual de novo sequencing followed by a homology-based search for identifying the allergenic proteins. N-terminal acetylation helped to distinguish "b" ions from others, facilitating reliable sequencing. This led to the identification of 12 allergenic proteins. Cluster analysis with individual patient sera recognized vicilin-like protein as a major allergen, which was purified to assess its in vitro allergenicity and then partially sequenced. Other IgE-sensitive spots showed significant homology with well-known allergenic proteins such as 11S globulin, enolase, and isoflavone reductase along with a few which are reported as novel allergens. The allergens identified can be used as potential candidates to develop hypoallergenic vaccines, to design specific immunotherapy trials, and to enrich the repertoire of existing IgE reactive proteins.

A novel antifungal peptide from foxtail millet seeds

BACKGROUND

Antifungal proteins (AFP) help plants to combat phytopathogenic fungi and thus protect plants from the devastating damage caused by fungal infections and prevent massive economic losses. To date, several proteins with antibacterial and/or antifungal properties have been isolated and characterized from different plant species and tissues; however, there are no reports concerning the antifungal peptide from foxtail millet seeds.

RESULTS

An antifungal peptide with a molecular mass of 26.9 kDa was isolated from dry seeds of the foxtail millet (Setaria italica (L.) Beauv.), using a procedure that involved four chromatographic steps. The antifungal peptide was adsorbed on CM-Sepharose, Affi-gel blue gel and Superdex 75. It was further purified by C(18) reverse-phase high-performance liquid chromatography and submitted for analysis of peptide mass fingerprint. The Mascot peptide mass fingerprint of the isolated protein hit no existing protein (score >60), and it was proved to be a novel antifungal peptide. It inhibited mycelial growth in Alternaria alternate with an IC(50) of 1.3 µmol L(-1) , and it also exhibited antifungal activity against Trichoderma viride, Botrytis cinerea and Fusarium oxysporum. Transmission electron microscopy of mold forms of Alternaria alternate after incubation with 20 µg mL(-1) of the antifungal protein for 48 h revealed marked ultrastructural changes in the fungus.

CONCLUSION

A novel antifungal peptide with high potency was isolated from foxtail millet seeds.

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.

Antibacterial peptides from plants: what they are and how they probably work

Plant antibacterial peptides have been isolated from a wide variety of species. They consist of several protein groups with different features, such as the overall charge of the molecule, the content of disulphide bonds, and structural stability under environmental stress. Although the three-dimensional structures of several classes of plant peptides are well determined, the mechanism of action of some of these molecules is still not well defined. However, further studies may provide new evidences for their function on bacterial cell wall. Therefore, this paper focuses on plant peptides that show activity against plant-pathogenic and human-pathogenic bacteria. Furthermore, we describe the folding of several peptides and similarities among their three-dimensional structures. Some hypotheses for their mechanisms of action and attack on the bacterial membrane surface are also proposed.

First report of an antifungal amidase from Peltophorum pterocarpum. [corrected]

A 60 kDa antifungal amidase was purified from Peltophorum pterocarpum [corrected] seeds using an isolation procedure that entailed ion-exchange chromatography on Q-Sepharose, ion-exchange chromatography on DEAE-cellulose and FPLC-gel filtration on Superdex 75. Unlike most other antifungal proteins isolated previously, it was adsorbed on Q-Sepharose and DEAE-cellulose. The isolated protein, designated as peltopterin, exhibited an N-terminal amino acid sequence closely resembling those of amidases. It exhibited amidase activity and digested iodoacetamide with an optimum pH and temperature at pH 9 and 50 degrees C, respectively. It also hydrolyzed acrylamide and urea. It impeded mycelial growth in Rhizotonia solani with an IC(50) of 0.65 microm. Chitin deposition at hyphal tips in R. solani was observed by staining with Congo red after incubation with peltopterin. Its antifungal activity was stable throughout pH 0-14 and 25-100 degrees C. It potently inhibited HIV-1 reverse transcriptase with an IC(50) of 27 nm.

Peptide antibiotics: an alternative and effective antimicrobial strategy to circumvent fungal infections

Mycosis, caused by both filamentous fungi and pathogenic yeasts is a major concern nowadays especially in the immunocompromised patient population. The emergence of pathogenic fungi resistant to current therapies in the last few decades has intensified the search for new antifungals like cationic peptides, which are the key components of innate defense mechanism. The review provides an inventory of different peptides from a diverse array of organisms from bacteria to mammals with proven antifungal activity, their therapeutic options and also about those which are in various stages of preclinical development. Literature, on the total and semi-synthetic variants of the parent peptides that exhibit an improved antifungal activity is also reviewed.

Identification and structural insights of three novel antimicrobial peptides isolated from green coconut water

Infections caused by pathogenic bacteria could cause an expressive negative impact on human health. A significant enhance in resistance to commercial antibiotics has been observed in all kinds of pathogenic bacteria. In order to find novel approaches to control such common infections, a wide number of defense peptides with bactericidal properties have been characterized. In this report, three peptides lower than 3kDa were purified and identified from green coconut (Cocos nucifera L.) water by using reversed phase-high performance liquid chromatography (HPLC), showing molecular masses of 858Da, 1249Da and 950Da. First one, named Cn-AMP1, was extremely efficient against both Gram-positive and Gram-negative bacteria, being MICs calculated for three peptides. All complete sequences were determined by MALDI-ToF analysis showing no identity in databanks. Moreover, peptide net charge and hydrophobicity of each peptide was in silico evaluated. Finally molecular modeling and dynamics were also applied generating peptides three-dimensional structures, indicating a better explanation to probable mechanisms of action. Cn-AMPs here reported show remarkable potential to contribute in the development of novel antibiotics from natural sources.