Bromelain and ficin proteolytic effects on gliadin cytotoxicity and expression of genes involved in cell-tight junctions in Caco-2 cells.

Enzyme therapy for celiac disease (CeD), which digests gliadin into non-immunogenic and non-toxic peptides, can be an appropriate treatment option for CeD. Here, we have investigated the effectiveness of bromelain and ficin on gliadin digestion using in vitro, such as SDS-PAGE, HPLC, and circular dichroism (CD). Furthermore, the cytotoxicity of gliadin and 19-mer peptide before and after digestion with these enzymes was evaluated using the MTT assay in the Caco-2 cell line. Finally, we examined the effect of these treatments along with Larazotide Acetate on the expression of genes involved in cell-tight junctions, such as Occludin, Claudin 3, tight junction protein-1, and Zonulin in the Caco-2 cell line. Our study demonstrated bromelain and ficin digestion effects on the commercial and wheat-extracted gliadin by SDS-PAGE, HPLC, and CD. Also, the cytotoxicity results on Caco-2 showed that toxicity of the gliadin and synthetic 19-mer peptide was decreased by adding bromelain and ficin. Furthermore, the proteolytic effects of bromelain and ficin on gliadin indicated the expression of genes involved in cell-tight junctions was improved. This study confirms that bromelain and ficin mixture could be effective in improving the symptoms of CeD.

Comparison of solid-phase red cell adherence and microcolumn agglutination technology using untreated and enzyme-treated red blood cells.

Screening for clinically significant antibodies is crucial in transfusion medicine and is a routine part of pre-transfusion testing. The indirect antiglobulin test (IAT) is the most reliable and effective test for detecting clinically significant alloantibodies reacting at the antihuman globulin phase. Two of the main methods used for antibody detection and identification are solid-phase red cell adherence (SPRCA) and microcolumn agglutination technology (CAT), with or without enzyme-treated red blood cells (RBCs). This study was undertaken to detect and identify alloantibodies by performing antibody screen (ABS) and antibody identification (ABID) testing using SPRCA and CAT, with and without ficin-treated RBCs. Residual patient samples collected between 1 December 2020 and 19 May 2021 were saved, de-identified, and frozen at ≤-30°C before testing for alloantibodies. Seventy antibodies were detected in 53 samples among the 203 samples that underwent an ABS. Of those samples, 150 (73.0%) were nonreactive, 47 (23.1%) yielded positive results with both CAT and SPRCA, and six (3.0%) yielded positive ABS results with SPRCA only. Fifty-three samples that underwent ABID by both methods yielded eight samples with antibodies identified by SPRCA only. Additional enhancement of the CAT method by the use of ficin-treated RBCs was required to detect seven of the eight SPRCA-only antibodies; one sample remained nonreactive regardless. SPRCA testing detected clinically significant antibodies without the addition of enzyme-treated RBCs that was necessary in the CAT testing.

Ficin-copper hybrid nanoflowers with enhanced peroxidase-like activity for colorimetric detection of biothiols.

The proteolytic enzyme ficin exhibits peroxidase-like activity but it is low and insufficient for real applications. Herein, we developed ficin-copper hybrid nanoflowers and demonstrated that they have significantly enhanced peroxidase-like activity of over 6-fold higher than that of free ficin, with one of the lowest Km and highest kcat values among all reported ficin-based peroxidase-like nanozymes. This was most likely caused by the synergistic catalysis of co-existing ficin and crystalline copper phosphate within nanoflower matrices having a large surface area. The nanoflowers were easily prepared by incubating ficin and copper sulfate at ambient temperature, causing coordination interactions between ficin's amine/amide moieties and copper ions, followed by concomitant anisotropic growth of petals composed of copper phosphate crystals with ficin. When compared to free ficin and natural horseradish peroxidase, the resulting nanoflowers' affinity toward H2O2 was greatly increased, yielding Km values of half and one-tenth, respectively, as well as noticeably improved stability. The nanoflowers were then applied to colorimetric determination of biological thiols (biothiols), such as cysteine (Cys), glutathione (GSH), and homocysteine (Hcy), based on their inhibition of nanoflowers' peroxidase-like activity, producing reduced color intensities as the concentration of biothiols increased. This strategy achieved highly sensitive colorimetric determinations of Cys, GSH, and Hcy after only 25-min incubation. Additionally, using this technique, biothiols in human serum were successfully determined with excellent precision, suggesting the potential application of this technology in clinical settings, particularly in point-of-care testing environments.

Complexation of Bromelain, Ficin, and Papain with the Graft Copolymer of Carboxymethyl Cellulose Sodium Salt and N-Vinylimidazole Enhances Enzyme Proteolytic Activity.

This study investigates the features of interactions between cysteine proteases (bromelain, ficin, and papain) and a graft copolymer of carboxymethyl cellulose sodium salt with N-vinylimidazole. The objective is to understand the influence of this interactions on the proteolytic activity and stability of the enzymes. The enzymes were immobilized through complexation with the carrier. The interaction mechanism was examined using Fourier-transform infrared spectroscopy and flexible molecular docking simulations. The findings reveal that the enzymes interact with the functional groups of the carrier via amino acid residues, resulting in the formation of secondary structure elements and enzyme's active sites. These interactions induce modulation of active site of the enzymes, leading to an enhancement in their proteolytic activity. Furthermore, the immobilized enzymes demonstrate superior stability compared to their native counterparts. Notably, during a 21-day incubation period, no protein release from the conjugates was observed. These results suggest that the complexation of the enzymes with the graft copolymer has the potential to improve their performance as biocatalysts, with applications in various fields such as biomedicine, pharmaceutics, and biotechnology.

The Effect of Ficin Immobilized on Carboxymethyl Chitosan on Biofilms of Oral Pathogens.

In the last decade, Ficin, a proteolytic enzyme extracted from the latex sap of the wild fig tree, has been widely investigated as a promising tool for the treatment of microbial biofilms, wound healing, and oral care. Here we report the antibiofilm properties of the enzyme immobilized on soluble carboxymethyl chitosan (CMCh) and CMCh itself. Ficin was immobilized on CMCh with molecular weights of either 200, 350 or 600 kDa. Among them, the carrier with a molecular weight of 200 kDa bound the maximum amount of enzyme, binding up to 49% of the total protein compared to 19-32% of the total protein bound to other CMChs. Treatment with pure CMCh led to the destruction of biofilms formed by Streptococcus salivarius, Streptococcus gordonii, Streptococcus mutans, and Candida albicans, while no apparent effect on Staphylococcus aureus was observed. A soluble Ficin was less efficient in the destruction of the biofilms formed by Streptococcus sobrinus and S. gordonii. By contrast, treatment with CMCh200-immobilized Ficin led to a significant reduction of the biofilms of the primary colonizers S. gordonii and S. mutans. In model biofilms obtained by the inoculation of swabs from teeth of healthy volunteers, the destruction of the biofilm by both soluble and immobilized Ficin was observed, although the degree of the destruction varied between artificial plaque samples. Nevertheless, combined treatment of oral Streptococci biofilm by enzyme and chlorhexidine for 3 h led to a significant decrease in the viability of biofilm-embedded cells, compared to solely chlorhexidine application. This suggests that the use of either soluble or immobilized Ficin would allow decreasing the amount and/or concentration of the antiseptics required for oral care or improving the efficiency of oral cavity sanitization.

Thermostable ficin from jelly fig (Ficus pumila var. awkeotsang) latex: purification, identification and characterization.

BACKGROUND: The achenes/seeds of endemic jelly fig (Ficus pumila var. awkeotsang) fruit have been applied to prepare a traditional beverage in Taiwan. Upon fruit harvest, jelly fig latex exuded from stalks was discarded. Protease activity was monitored in its latex. Proteases capable of hydrolyzing proteins have many application aspects based on diverse characteristics. Commercial plant proteases are frequently from latex. RESULTS: The latex protease of jelly fig, termed FaFicin, was purified to homogeneity with a molecular mass of ~32 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. According to liquid chromatographic-tandem mass spectrometric analyses, the expected protein band of protease was matched to ficin A, ficin B or chymopapain from common fig or papaya. Iodoacetamide, an inhibitor of cysteine protease, inhibited its protease activity completely. Hence FaFicin was identified as a papain-like cysteine protease (PLCP), exhibiting more than 80% and 70% activity as assayed at pH 5-8 and 40-70 °C, respectively. It maintained ~89% of initial activity after 120 min at 55 °C and pH 7. Moreover, FaFicin could degrade the myosin and actin of meat, and clot milk. CONCLUSION: The ficin FaFicin was obtained, purified and identified as a PLCP member from agricultural waste: jelly fig latex. It possessed activity under a wide range of pH values and temperature, and exhibited excellent thermostability. Based on its initial evaluation as a meat tenderizer and milk clotting reagent, the application of FaFicin was possible, which may extend utilization of jelly fig. © 2022 Society of Chemical Industry.

ACE2-Inhibitory Effects of Bromelain and Ficin in Colon Cancer Cells.

Background and Objectives: Bromelain and ficin are aqueous extracts from fruits of Ananas comosus and Ficus carcia plants, used widely for medical applications. Angiotensin-converting enzyme 2 (ACE2) is a homolog of ACE, degrading Ang II to angiotensin 1-7 and decreasing the cellular concentration of Ang II. Materials and Methods: In this study, we investigated the ACE2-inhibitory, antiproliferative, and apoptosis-inducing effects of ficin and bromelain on caco-2 cells. Results: We found that bromelain and ficin significantly reduced the viability of human colon cancer cells with IC50 value concentrations of 8.8 and 4.2 mg/mL for bromelain after 24 and 48 h treatments, and 8.8 and 4.2 mg/mL for ficin after 24 and 48 h treatments, respectively. The apoptosis of the caco-2 cell line treated with bromelain was 81.04% and 56.70%, observed after 24 and 48 h. Total apoptotic proportions in caco-2 cells treated with ficin after 24 and 48 h were 83.7% and 73.0%. An amount of 1.6 mg/mL of bromelain and ficin treatments on caco-2 cells after 24 h revealed a higher decrease than that of other concentrations in the expression of ACE2 protein. Conclusions: In conclusion, bromelain and ficin can dose-dependently decrease the expression of ACE2 protein in caco-2 cells.

Efficacy of ficin and peroxyacetic acid against Salmonella enterica serovar Thompson biofilm on plastic, eggshell, and chicken skin.

Salmonella is the leading cause of zoonotic foodborne illnesses worldwide and a prevalent threat to the poultry industry. For controlling contamination, the use of chemical sanitizers in combination with biological compounds (e.g., enzymes) offers a solution to reduce the chemical residues. The current study investigated the biofilm reduction effects of a food-grade enzyme-ficin-and a common sanitizer-peroxyacetic acid (PAA)-against an emerging pathogen, Salmonella enterica ser. Thompson, on plastic, eggshell, and chicken skin surfaces. Results showed that PAA could kill S. Thompson, but ficin cannot. Maximum biofilm reduction was 3.7 log CFU/cm2 from plastic after individual treatment with PAA. However, sequential treatment of ficin and PAA led to biofilm reductions of 3.2, 5.0, and 6.5 log CFU/cm2 from chicken skin, eggshell, and plastic, respectively. Fourier-transform infrared spectroscopy and microscopic analysis confirmed that ficin increased PAA action, causing biofilm matrix destruction. Moreover, the quality of the food surfaces was only altered by 12.5 U/mL ficin and was not altered by PAA. This combined use of enzyme and sanitizer solved major safety issues and proved promising against S. Thompson-associated contaminations in poultry and poultry processing lines.

Enzyme treatment of red blood cells: use of ficin and papain.

Proteolytic enzymes are used to treat red blood cells (RBCs) to aid in complex antibody identification. Although there are many enzymes that can be used, for the purpose of this method review, enzyme-treated RBCs refers only to RBCs treated with ficin or papain. Ficin and papain can increase the sensitivity of antibody detection by modifying the RBC membrane. Enzyme treatment and test methods can be performed using one-stage or two-stage procedures. Enzyme treatment is especially useful for the differentiation of multiple antibodies, enhancement of detection of weak antibodies, and adsorption methods. In all cases, quality control is required to ensure adequate treatment of RBCs before additional testing. Ficin and papain are useful tools for both immunohematology reference laboratories and transfusion services.

Inhibitory effect of ficin on Candida albicans biofilm formation and pre-formed biofilms.

BACKGROUND: To investigate the effect of ficin, a type of proteases, on Candida albicans (C. albicans) biofilm, including forming and pre-formed biofilms. METHODS: Crystal violet tests together with colony forming unit (CFU) counts were used to detect fungal biofilm biomass. Live/dead staining of biofilms observed by confocal laser scanning microscopy was used to monitor fungal activity. Finally, gene expression of C. albicans within biofilms was assessed by qRT-PCR. RESULTS: According to our results, biofilm biomass was dramatically reduced by ficin in both biofilm formation and pre-formed biofilms, as revealed by the crystal violet assay and CFU count (p < 0.05). Fungal activity in biofilm formation and pre-formed biofilms was not significantly influenced by ficin according to live/dead staining. Fungal polymorphism and biofilm associated gene expression were influenced by ficin, especially in groups with prominent antibiofilm effects. CONCLUSIONS: In summary, ficin effectively inhibited C. albicans biofilm formation and detached its preformed biofilm, and it might be used to treat C. albicans biofilm associated problems.

Production and Characterization of Antioxidative Hydrolysates and Peptides from Corn Gluten Meal Using Papain, Ficin, and Bromelain.

There has been a growing interest in developing natural antioxidants with high efficiency and low cost. Bioactive protein hydrolysates could be a potential source of natural and safer antioxidants. The objectives of this study were to hydrolyze corn gluten meal using three plant-derived proteases, namely papain, ficin, and bromelain, to produce antioxidative hydrolysates and peptides and to characterize the antioxidant performances using both chemical assays and a ground meat model. The optimum hydrolysis time for papain was 3 h, and for ficin and bromelain was 4 h. The hydrolysates were further separated by sequential ultrafiltration to 5 hydrolysate fractions named F1 to F5 from low molecular weight (MW) (<1 kDa) to high MW range (>10 kDa), which were further characterized for TPC, free radical scavenging capacity against DPPH and ABTS, and metal chelating activity. The fraction F4 produced by papain (CH-P4), F1 produced by ficin (CH-F1), and F3 produced by bromelain (CH-B3) showed the strongest antioxidant activity and yield, respectively. These three fractions were incorporated into ground pork to determine their inhibition effects on lipid oxidation during a 16-day storage period. The inhibition effect was enhanced with the addition of higher amount of hydrolysate (e.g., 1000 vs. 500 mg/kg). The CH-P4 reduced lipid oxidation in ground meat by as much as 30.45%, and CH-B3 reduced oxidation by 27.2% at the same level, but the inhibition was only 13.83% with 1000 mg/kg of CH-F1. The study demonstrated that CGM protein hydrolysates and peptides could be used as naturally derived antioxidant in retarding lipid oxidation and improving product storage stability.

Comparative stability of ficin and papain in acidic conditions and the presence of ethanol.

Proteolytic enzymes are used for proteolysis and peptide synthesis which can be run in various conditions including low pH value and the presence of ethanol. The most common cysteine protease applied in acidic-alcoholic conditions is well-characterized papain. Ficin, which is closely related to papain in terms of proteolytic activity and substrate specificity, could potentially be applied in the alcoholic beverage industry and peptide synthesis. The aim of this study was to compare papain and ficin stability in process conditions. Comparative stability study showed that ficin as a mixture of different isoforms has a broader range of stability in respect of pH and cold storage stability, in comparison to papain. It retains about 70% of initial activity after 3-week cold storage at low pH and in the presence of ethanol. Unlike ficin, papain loses about 70% of initial activity in the same incubation period as it is more prone to non-native aggregation that was confirmed by FTIR analysis. The presence of multiple isoforms of ficin stabilizes the protease against cold denaturation and aggregation, making it more suitable for biotechnological and laboratory usage than single papain isoform. It is more cold-stable in alcoholic-acidic and acidic conditions suggesting possible replacement of papain with even lower enzyme concentration.

One-pot synthesis of a composite consisting of the enzyme ficin and a zinc(II)-2-methylimidazole metal organic framework with enhanced peroxidase activity for colorimetric detection for glucose.

An enzyme-metal organic framework (MOF) composite with saucer-like structure was prepared via one-pot synthesis from ficin (a cysteine proteolytic enzyme with POx activity), zinc(II) ions and 2-methylimidazole. The composites exhibit a 2.5-fold higher catalytic activity and stronger affinity for substrates compared to free ficin. This was exploited to design a colorimetric assay for the determination of glucose. The addition of glucose oxidase causes the formation of H2O2 which is catalytically oxidized by ficin to form a blue coloration that can be measured at 652 nm. The assay has a 0.12 µM detection limit and excellent selectivity. It was successfully applied to the determination of glucose in diluted serum samples. Graphical abstract Schematic presentation of the synthesis process and the enhanced peroxidase activity of ficin@MOF composites. Ficin was immobilized in a new saucer-like shape of Ficin@MOF composites, which showed higher peroxidase activity than free ficin. Scheme and graphical abstract contains poor quality of text.We have attach a new picture with 600 dpi as scheme and graphical abstract.

Production of highly and broad-range specific monoclonal antibodies against hemagglutinin of H5-subtype avian influenza viruses and their differentiation by mass spectrometry.

BACKGROUND: The highly pathogenic avian influenza viruses of the H5 subtype, such as the H5N1 viral strains or the novel H5N8 and H5N2 reassortants, are of both veterinary and public health concern worldwide. To combat these viruses, monoclonal antibodies (mAbs) against H5 hemagglutinin (HA) play a significant role. These mAbs are effective diagnostic and therapeutic agents and powerful tools in vaccine development and basic scientific research. The aim of this study was to obtain diagnostically valuable mAbs with broad strain specificity against H5-subtype AIVs. RESULTS: We applied the hybridoma method to produce anti-HA mAbs. The cloning and screening procedures resulted in the selection of 7 mouse hybridoma cell lines and their respective antibody clones. Preliminary immunoreactivity studies showed that these newly established mAbs, all of the IgG1 isotype, had high specificity and broad-range activities against the H5 HAs. However, these studies did not allow for a clear distinction among the selected antibodies and mAb-secreting hybridoma clones. To differentiate the analyzed mAbs and determine the exact number of hybridoma clones, peptide mapping of the Fc and Fab fragments was performed using a Matrix-Assisted Laser Desorption Ionization Time of Flight (MALDI-TOF/TOF) mass spectrometer. Detailed analyses of the acquired MS and MS/MS spectra confirmed that the Fc fragments constituted highly conserved species- and isotype-immunoglobulin components, whereas the Fab fragments exhibited considerable variation in the sequences that determine antibody specificity. This approach enabled unambiguous characterization of the selected mAbs according to their peptide composition. As a result, 6 different clones were distinguished. CONCLUSIONS: Our work provided a unique panel of anti-H5 HA mAbs, which meets the demand for novel, high-specificity analytical tools for use in serologic surveillance. Applications of these mAbs in areas other than diagnostics are also possible. Moreover, we demonstrated for the first time that peptide mapping of antibody fragments with mass spectrometry is an efficient method for the differentiation of antibody clones and relevant antibody-producing cell lines. The method may be successfully used to characterize mAbs at the protein level.

Characterisation of general proteolytic, milk clotting and antifungal activity of Ficus carica latex during fruit ripening.

BACKGROUND: The physiological role of fig latex is to protect the plant from pathogens. Latex is a rich source of proteases, predominantly ficin. Fig latex also contains collagenolytic protease and chitinolytic enzymes. Our aim was to investigate changes in protein composition, enzyme and antifungal activities of fig latex during fruit ripening. RESULTS: Comparison of latex samples in different time periods showed a uniform increase of protein concentration in chronological order. The content of collagenolytic protease did not differ significantly in the latex samples, while the content of ficin decreased. Ficin-specific activity towards casein was the highest at the beginning of fruit development (about 80 U mg(-1)). Specific milk clotting activity increased as well as the abundance of casein band in the clots. Specific chitinolytic activity at the beginning of flowering was 6.5 times higher than the activity in the period when fruits are ripe. Antifungal activity is the most extensive in spring. CONCLUSION: Ficin forms with different casein specificities are present in different proportions during fruit ripening, which is of importance for applications in the dairy industry. The protection mechanism against insects and fungi, which relies on chitinolytic activity, is the most important in the early phases of flowering and is replaced with other strategies over time.

Optimizing tenderness of M. Semitendinosus steak for elderly people with the combination of ficin and sous-vide cooking.

This study aimed to evaluate the sous-vide cooking and ficin treatment effects on the tenderness of beef steak and optimize it for the elderly using response surface methodology (RSM). The M. semitendinosus (ST) from Chikso cattle was shaped into 5 × 5 × 2.54 cm pieces. Ficin solution was injected into the ST steak at 10% of the meat weight, and sous-vide cooked in a water bath at 65 °C for 6 or 12 h. As ficin concentration increased, L*- and a*-value, shear force, and hardness decreased, while soluble peptides increased (P < 0.05). As cooking time increased, cooking loss and collagen solubility of the steak increased (P < 0.05). An interaction effect between ficin and sous-vide cooking was found in L*- and a*-value, shear force, hardness, and soluble peptides (P < 0.05). A model to optimize the hardness for elderly people was established (R2 = 0.7991). Optimization conditions by RSM were 0.86 U/L with 8.87 h (23 N/cm3) for tooth intake (grade 1), 16.31 U/L with 13.24 h (3 N/cm3) for gums intake (grade 2), according to KS H 4897 and Universal Design Foods concept for the elderly. These optimized conditions enable the production of customized products tailored to the oral conditions of elderly people.

Effect of ficin-hydrolyzed wheat gluten on bread quality and in vitro antioxidant activity before and after simulated gastrointestinal digestion.

This study aimed to investigate the effect of adding ficin-hydrolyzed wheat gluten at different levels (0%, 1%, 2%, 4%) on bread quality, and in vitro antioxidant activity before and after simulated gastrointestinal digestion. Our findings revealed that the incorporation of the generated wheat gluten hydrolysates (WGH) up to 4 g per 100 g flour positively affected the technological and physical-chemical characterizations of breads, including dough rheological properties, color, specific volume, and moisture. The texture profile analysis indicated reductions in hardness, springiness, and chewiness of the breads, and confirmed anti-staling properties during storage. The enriched breads received satisfactory scores from the sensory panel and were perceived as less stale after a 4-day period of storage. The aroma score of the 4% WGH bread was significantly higher than other treatments. Regarding taste, the 4% WGH bread scored the lowest, but the obtained value was not statistically significant. The enriched breads exhibited DPPH, ABTS radical scavenging, and Fe2+ chelation abilities that increased in response to higher levels of hydrolysate incorporation, and these antioxidant activities were enhanced after simulated gastrointestinal digestion. Our findings confirm that it is possible to apply ficin-generated WGH to enhance physicochemical, nutritional, and biological quality of bread.

Magnetic graphene oxide, a suitable support in ficin immobilization.

In the present study, we aimed to develop a fast, non-toxic ultrasonic-assisted technique for the preparation of graphene oxide (GO) and GO that were accessorized with Fe3O4 (GO-Fe3O4) for enzyme immobilization. The structural properties of nanosheets were determined by FTIR, XRD, and SEM. Immobilized enzymes on the GO-Fe3O4 and GO were counted. Enzyme activity, reusability, and improvements in enzyme stability were studied. According to the results, the immobilization efficiency was 256.86 mg ficin/GO (g), and 253.63 mg ficin/GO-Fe3O4 (g). Furthermore, immobilized ficin was affected in terms of stability by variations in pH and temperature. The immobilized ficin on the GO-Fe3O4 could be easily recycled from the reaction medium by applying external magnetic separation, involving 10 cycles for 120 days. Over this period and with this number of cycles, the immobilized enzyme on the GO-Fe3O4 retained 74% of its original activity, whereas the immobilized enzyme on the GO was recycled from the reaction medium after centrifuging, thereby retaining 70% of its original activity. Thus, GO and GO-Fe3O4 nanosheets were obtained efficiently from the ultrasonic-assisted technique and can be regarded as excellent nanocarriers for enzyme immobilization.

Carboxymethyl Cellulose-Based Polymers as Promising Matrices for Ficin Immobilization.

The present work is devoted to research on the interaction between carboxymethyl cellulose sodium salt and its derivatives (graft copolymer of carboxymethyl cellulose sodium salt and N,N-dimethyl aminoethyl methacrylate) with cysteine protease (ficin). The interaction was studied by FTIR and by flexible molecular docking, which have shown the conjugates' formation with both matrices. The proteolytic activity assay performed with azocasein demonstrated that the specific activities of all immobilized ficin samples are higher in comparison with those of the native enzyme. This is due to the modulation of the conformation of ficin globule and of the enzyme active site by weak physical interactions involving catalytically valuable amino acids. The results obtained can extend the practical use of ficin in biomedicine and biotechnology.

Comparative Analysis of the Immune Response and the Clinical Allergic Reaction to Papain-like Cysteine Proteases from Fig, Kiwifruit, Papaya, Pineapple and Mites in an Italian Population.

Several plant papain-like cysteine proteases are exploited by the food, cosmetic, pharmaceutical and textile industries. However, some of these enzymes can cause allergic reactions. In this context, we investigated the frequency of sensitization and allergic reactions to some fruit and/or latex cysteine proteases, which are used as additives by the food industry to improve and modify the quality of their products. The FABER test was used to analyse the patients' sensitization towards five plants and, for comparison, two homologous mite cysteine proteases. In an Italian population of 341 allergic patients, 133 (39%) had IgE specific for at least one of the seven cysteine proteases under investigation. Most of the patients were IgE positive for Der p 1 and/or Der f 1 (96.38%) reported a clinical history suggestive of respiratory allergy to mites, whereas none of the subjects sensitized to the homologs from papaya, pineapple and fig reported allergy symptoms following ingestion of these foods. Only one patient referred symptoms from ingesting kiwifruit. Therefore, the obtained results showed that sensitization to the fruit enzymes was only rarely concomitant with allergic reactions. These observations, together with the literature reports, suggest that the allergy to plant papain-like cysteine proteases might mainly be an occupational disease.