Purification and characterization of hydrolase with chitinase and chitosanase activity from commercial stem bromelain

Bromelain a Potential Bioactive Compound: A Comprehensive Overview from a Pharmacological Perspective

Bromelain is an effective chemoresponsive proteolytic enzyme derived from pineapple stems. It contains several thiol endopeptidases and is extracted and purified via several methods. It is most commonly used as an anti-inflammatory agent, though scientists have also discovered its potential as an anticancer and antimicrobial agent. It has been reported as having positive effects on the respiratory, digestive, and circulatory systems, and potentially on the immune system. It is a natural remedy for easing arthritis symptoms, including joint pain and stiffness. This review details bromelain's varied uses in healthcare, its low toxicity, and its relationship to nanoparticles. The door of infinite possibilities will be opened up if further extensive research is carried out on this pineapple-derived enzyme.

Novel Glycosylated Naphthalimide-Based Activatable Fluorescent Probe: A Tool for the Assessment of Hexosaminidase Activity and Intracellular Hexosaminidase Imaging

The development of effective detection methods for hexosaminidase is of great importance for the rapid screening of potential inhibitors in vitro and for the early diagnosis of related diseases ex vivo. In this study, the activatable fluorescent probes that are based on naphthalimide decorated with ethylene glycol units were synthesized using N-acetyl-β-d-glucosaminide as a hexosaminidase-responsive group. When exposed to this enzyme, the glucoside-linked naphthalimide moiety of 1c can be cleaved quickly with significant changes in both color (from colorless to yellow) and fluorescence (from blue to green). Probe 1c shows better water-solubility and fluorescence properties than common substrate 4-methylumbelliferyl N-acetyl-β-d-glucosaminide. Furthermore, the response mechanism of 1c to hexosaminidase was evaluated using HPLC analysis and TD-DFT calculations. Molecular docking was performed to investigate the interaction mode. In addition, 1c has successfully achieved the straightforward rapid discovery of effective hexosaminidase inhibitors. Fluorescence imaging experiments indicate that 1c has good cell safety and can be employed as a useful tool for detecting intracellular hexosaminidase activity.

Molecular Cloning, Expression, and Functional Characterization of a Cystatin from Pineapple Stem

A cDNA fragment encoding the cysteine protease inhibitor, cystatin, was cloned from pineapple (Ananas comosus) stem. This clone was constructed in a fusion vector and was easily over-expressed in Escherichia coli; satisfactory over-expression of non-fusion cystatin was achieved after an additional start codon was inserted prior to its coding sequence. Both recombinant cystatins were predominately found in the soluble fraction of the cell extract, and were demonstrated to be functionally active in a reverse zymographic assay. The fusion and non-fusion cystatins were separately purified to homogeneity via a His-tag or papain-coupling affinity column. Effective inhibitory activity against papain was detected with both the fusion and non-fusion cystatins with comparable K(i) values of 1.18 x 10(-10) M and 9.53 x 10(-11) M, respectively. The recombinant cystatins were found to be thermally stable up to 60 degrees C. Inhibition of the endogenous protease activity in minced fish muscle revealed that the recombinant pineapple cystatins might be an adequate stabilizer to prevent protein degradation during industrial food processing.

Anticancer effect of bromelain with and without cisplatin or 5-FU on malignant peritoneal mesothelioma cells

Malignant peritoneal mesothelioma (MPM) is a rare neoplasm of the peritoneum, causally related to asbestos exposure. Nonspecific symptoms with a late diagnosis results in poor survival (<1 year). Treatment with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy has improved survival in some patients (median 3-5 years). Hence, new therapies are urgently needed. MUC1 is a glycosylation-dependent protein that confers tumours with invasiveness, metastasis and chemoresistance. Bromelain (cysteine proteinase) hydrolyses glycosidic bonds. Therefore, we investigated the antitumour effect of bromelain on MUC1-expressing MPM cell lines. MUC1 expressions in cells were assessed using immunofluorescent probes with cells grown on cover slips and western blot analysis on cell lysates. The cell lines were treated with various concentrations of bromelain and after 4 and 72 h, their viability was assessed using standard sulforhodamine assays. The cells were also treated with combinations of bromelain and cytotoxic drugs (cisplatin or 5-FU) and their viability was assessed at 72 h. Finally, with western blotting, the effects of bromelain on cellular survival proteins were investigated. PET cells expressed more MUC1 compared with YOU cells. The cell viability of both PET and YOU cells was adversely affected by bromelain, with PET cells being slightly resistant. The addition of bromelain increased the cytotoxicity of cisplatin significantly in both cell lines. However, 5-FU with bromelain did not show any significant increase in cytotoxicity. Bromelain-induced cell death is by apoptosis and autophagy. Bromelain has the potential of being developed as a therapeutic agent in MPM.

Purification and properties of a Meloidogyne-antagonistic chitinase from Lysobacter capsici YS1215

The root-knot nematodes, Meloidogyne spp., cause serious diseases in various plants and their chemical control may lead to environmental problems. Therefore, alternative control measures against the phytopathogenic nematodes are being sought. One of the potential targets against Meloidogyne spp. may be the chitinolysis and degradation of nematode eggs. Therefore, in the present study, a chitinolytic and nematicidal strain of Lysobacter capsici YS1215 was isolated from an agricultural field in Korea. The aim of this study was to purify chitinase secreted by L. capsici YS1215 and investigate its nematicidal role against Meloidogyne incognita. The chitinase secreted by L. capsici YS1215 was purified by protein precipitation with 80% ammonium sulphate, anion-exchange chromatography with DEAE-cellulose and gel-filtration chromatography with Sephadex G-100. By chitinase-active staining of the purified enzyme, a single band was obtained with an estimated molecular mass of 43.6 kDa. The optimal pH and optimal temperature for the highest chitinase activity were 6.0 and 40°C, respectively. The purified chitinase degraded the chitin layer of the eggshells and significantly reduced hatch of second-stage juveniles. The activity of chitinase secreted by L. capsici YS1215 was not affected by CoCl2, MnCl2, MgCl2, CuSO4, CaCl2 or EDTA. The purified enzyme could also hydrolyse swollen chitin, glycol chitin, glycol chitosan and chitin powder. Thus, the role of chitinase secreted by L. capsici YS1215 against Meloidogyne spp. may be useful for further development of a biocontrol agent.

Two cold-induced family 19 glycosyl hydrolases from cherimoya (Annona cherimola) fruit: an antifungal chitinase and a cold-adapted chitinase

Two cold-induced chitinases were isolated and purified from the mesocarp cherimoyas (Annona cherimola Mill.) and they were characterised as acidic endochitinases with a Mr of 24.79 and 47.77kDa (AChi24 and AChi48, respectively), both family 19 glycosyl hydrolases. These purified chitinases differed significantly in their biochemical and biophysical properties. While both enzymes had similar optimal acidic pH values, AChi24 was enzymatically active and stable at alkaline pH values, as well as displaying an optimal temperature of 45°C and moderate thermostability. Kinetic studies revealed a great catalytic efficiency of AChi24 for oligomeric and polymeric substrates. Conversely, AChi48 hydrolysis showed positive co-operativity that was associated to a mixture of different functional oligomeric states through weak transient protein interactions. The rise in the AChi48 kcat at increasing enzyme concentrations provided evidence of its oligomerisation. AChi48 chitinase was active and stable in a broad acidic pH range, and while it was relatively labile as temperatures increased, with an optimal temperature of 35°C, it retained about 50% of its maximal activity from 5 to 50°C. Thermodynamic characterisation reflected the high kcat of AChi48 and the remarkably lower ΔH(‡), ΔS(‡) and ΔG(‡) values at 5°C compared to AChi24, indicating that the hydrolytic activity of AChi48 was less thermodependent. In vitro functional studies revealed that AChi24 had a strong antifungal defence potential against Botrytis cinerea, whereas they displayed no cryoprotective or antifreeze activity. Hence, based on biochemical, thermodynamic and functional data, this study demonstrates that two acidic endochitinases are induced at low temperatures in a subtropical fruit, and that one of them acts in an oligomeric cold-adapted manner.

Biochemistry and physiological roles of enzymes that 'cut and paste' plant cell-wall polysaccharides

The plant cell-wall matrix is equipped with more than 20 glycosylhydrolase activities, including both glycosidases and glycanases (exo- and endo-hydrolases, respectively), which between them are in principle capable of hydrolysing most of the major glycosidic bonds in wall polysaccharides. Some of these enzymes also participate in the 'cutting and pasting' (transglycosylation) of sugar residues-enzyme activities known as transglycosidases and transglycanases. Their action and biological functions differ from those of the UDP-dependent glycosyltransferases (polysaccharide synthases) that catalyse irreversible glycosyl transfer. Based on the nature of the substrates, two types of reaction can be distinguished: homo-transglycosylation (occurring between chemically similar polymers) and hetero-transglycosylation (between chemically different polymers). This review focuses on plant cell-wall-localized glycosylhydrolases and the transglycosylase activities exhibited by some of these enzymes and considers the physiological need for wall polysaccharide modification in vivo. It describes the mechanism of transglycosylase action and the classification and phylogenetic variation of the enzymes. It discusses the modulation of their expression in plants at the transcriptional and translational levels, and methods for their detection. It also critically evaluates the evidence that the enzyme proteins under consideration exhibit their predicted activity in vitro and their predicted action in vivo. Finally, this review suggests that wall-localized glycosylhydrolases with transglycosidase and transglycanase abilities are widespread in plants and play important roles in the mechanism and control of plant cell expansion, differentiation, maturation, and wall repair.

Chitinases: in agriculture and human healthcare

Biological control of phytopathogenic fungi and insects continues to inspire the research and development of environmentally friendly bioactive alternatives. Potentially lytic enzymes, chitinases can act as a biocontrol agent against agriculturally important fungi and insects. The cell wall in fungi and protective covers, i.e. cuticle in insects shares a key structural polymer, chitin, a β-1,4-linked N-acetylglucosamine polymer. Therefore, it is advantageous to develop a common biocontrol agent against both of these groups. As chitin is absent in plants and mammals, targeting its metabolism will signify an eco-friendly strategy for the control of agriculturally important fungi and insects but is innocuous to mammals, plants, beneficial insects and other organisms. In addition, development of chitinase transgenic plant varieties probably holds the most promising method for augmenting agricultural crop protection and productivity, when properly integrated into traditional systems. Recently, human proteins with chitinase activity and chitinase-like proteins were identified and established as biomarkers for human diseases. This review covers the recent advances of chitinases as a biocontrol agent and its various applications including preparation of medically important chitooligosaccharides, bioconversion of chitin as well as in implementing chitinases as diagnostic and prognostic markers for numerous diseases and the prospect of their future utilization.

Purification and characterization of two chitosanase isoforms from the sheaths of bamboo shoots

Two thermally stable chitosanase isoforms were purified from the sheaths of chitosan-treated bamboo shoots. Isoforms A and B had molecular masses of 24.5 and 16.4 kDa and isoelectric points of 4.30 and 9.22, respectively. Using chitosan as the substrate, both isoforms functioned optimally between pH 3 and 4, and the optimum temperatures for the activities of isoforms A and B were 70 and 60 °C, respectively. The kinetic parameters K(m) and V(max) for isoform A were 0.539 mg/mL and 0.262 μmol/min/mg, respectively, and for isoform B were 0.183 mg/mL and 0.092 μmol/min/mg, respectively. Chitosans were susceptible to degradation by both enzymes and could be converted to low molecular weight chitosans between 28.2 and 11.7 kDa. Furthermore, the most susceptible chitosan substrates were 50-70 and 40-80% deacetylated for isoforms A and B, respectively. Both enzymes could also degrade chitin substrates with lower efficacy. N-Bromosuccinimide and Woodward's reagent K strongly inhibited both enzymes.

Cloning and characterization of a bifunctional glycosyl hydrolase from an antagonistic Pseudomonas putida strain P3(4)

A fluorescent pseudomonad strain P3(4) showing chitinolysis on chitinase detection agar and antagonism against Fusarium oxysporum f.sp dianthi causing vascular wilt of carnation was isolated from pea rhizosphere soil. PCR primers specific for glycosyl hydrolase family 5 (GH5) of Pseudomonas putida isolate KT2440 amplified a 947 bp fragment of the GH5 gene from P3(4). Cloning of this gene into Escherichia coli M15 using an expression vector pQE-30UA and screening on chitin and chitosan detection agar identified one positive clone (Pchi(+) ). Sequence analysis of the cloned insert revealed an open reading frame of 947 nucleotides corresponding to a protein of 315 amino acids with a predicted molecular mass of 38.0 kDa. The deduced amino acid sequence of the open reading frame (gene product/GH) showed 83-84% homology to the GH5 of P. putida strains F1 and KT2440, respectively. The purified enzyme was homogenous, as examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and was visualized as single fluorescent band in native gel assay with 4-methylumbelliferyl-N -acetyl-β;-D-glucosaminide and glycol chitosan, respectively. For hydrolysis of 4-nitrophenyl-N -acetyl-β;-D-glucosaminide (pNP-(GlcNAc) and colloidal chitosan, the enzyme had an optimal temperature of 40 °C, and was stable within the temperature range of 10 °C to 40 °C. The enzyme showed an optimal pH of 3.5, with maximum stabilities at 5.0 and 5.5 for hydrolysis of pNP-(GlcNAc) and colloidal chitosan, respectively. Fe(3+) and Cu(2+) stimulated chitinase and chitosanase activities by 74.2 and 51.4%, respectively. The purified GH displayed 70 and 45% inhibition of spore germination of the pathogenic fungi, Fusarium oxysporum f.sp. dianthi and Alternaria solani, respectively.

Purification and characterization of an extracellular 24 kDa chitobiosidase from the mycoparasitic fungus Trichoderma saturnisporum

A Trichoderma saturnisporum Hamill isolate GITX-Panog (C) exhibiting strong chitinolytic and antifungal activity against Fusarium oxysporum f.sp. dianthi, the causal agent of vascular wilt in carnation was used to purify extracellular chitobiosidase using Czapek-Dox broth amended with the fungal mycelium as the carbon source. The protein was purified by precipitation with ammonium sulphate, followed by DEAE-Cellulose anion-exchange and Sephacryl S-200 high resolution gel filtration chromatography. The purity of the enzyme was determined by SDS-PAGE, with an estimated molecular mass of 24 kDa. In native gel assay with 4-methylumbelliferyl -N,N ' diacetyl-β-D-chitobioside (4-Mu-(GluNAc)(2) , the purified chitobiosidase was visualized as single fluorescent band. Enzyme activity towards short oligomeric natural substrates indicated that the enzyme has properties that are characteristic to exochitinases. The enzyme was active up to 60 °C and at pH 4.0, and displayed maximum stability at 50 °C. Mn(2+) and Zn(2+) stimulated the enzyme activity by 63% and 41%, respectively. The K(m) and V(max) values of the purified enzyme for 4-Mu-(GluNAc)(2) were 338.9 μM ml(-1) and 0.119 μM ml(-1) min(-1) , respectively. This appears to be the first report of characterization of a chitobiosidase from antagonistic Trichoderma saturnisporum.

A family 19 chitinase (Chit30) from Streptomyces olivaceoviridis ATCC 11238 expressed in transgenic pea affects the development of T. harzianum in vitro

Embryo axes excised from mature seeds of pea (Pisum sativum L.) cv. 'Sponsor' were used as explants for Agrobacterium-mediated transformation using pGreenII 0229 binary vectors. The vectors harbored a chimeric chitinase gene (chit30), driven by the constitutive 35S promoter or the elicitor inducible stilbene synthase (vst) promoter from grape (Vitis vinifera L.). The secretion signal of the bacterial chitinase gene from Streptomyces olivaceoviridis ATCC 11238 (DSM 41433) was replaced by the A. thaliana basic chitinase leader sequence. Functional properties of the recombinant gene were tested in tobacco as a model system before the long process of pea transformation was undertaken. Several transgenic pea clones were obtained and the transgenic nature confirmed by different molecular methods. The accumulation and activity of chitinase in stably transformed plants were examined by Western blot analysis and in-gel assays, which showed the presence of an additional 3 isoform bands. Using in vitro bioassays with Trichoderma harzanium as a model, we found an inhibition or delay of hyphal extension, which might indicate enhanced antifungal activity compared with non-transformed pea plants. Up to the 4th generation, the transgenic plants did not show any phenotypic alterations compared with non-transgenic control plants.

Enzymatic preparation of chitooligosaccharides by commercial lipase

The effect of a commercial lipase on chitosan degradation was investigated. When four chitosans with various degrees of deacetylation were used as substrates, the lipase showed higher optimal pH toward chitosan with higher DD (degree of deacetylation). The optimal temperature of the lipase was 55°C for all chitosans. The enzyme exhibited higher activity to chitosans which were 82.8% and 73.2% deacetylated. Kinetics experiments show that chitosans with DD of 82.8% and 73.2% which resulted in lower Km values had stronger affinity for the lipase. The chitosan hydrolysis carried out at 37°C produced larger quantity of COS (chitooligosaccharides) than that at 55°C when the reaction time was longer than 6h, and COS yield of 24h hydrolysis at 37°C was 93.8%. Products analysis results demonstrate that the enzyme produced glucosamine and chitooligosaccharides with DP (degree of polymerization) of 2-6 and above, and it acted on chitosan in both exo- and endo-hydrolytic manner.

Safety evaluation of short-term exposure to chitooligomers from enzymic preparation

Chitooligomers have significant application to the development of functional foods. This paper evaluated systematically the safety of chitooligomers, which were prepared by enzymatic depolymerization of chitosan. The oral maximum tolerated dose of this chitooligomes was more than 10 g/kg body weight in mice. It had no mutagenicity judged by negative experimental results of Ames test, mouse bone marrow cell micronucleus test and mouse sperm abnormality test. A 30-day feeding study shows that no abnormal symptoms and clinical signs or deaths were found in rats during the test. There were no significant difference in body weight, food consumption and food availability of rats in each test group. No significant differences were found in each hematology value, clinical chemistry value and organ/body weight ratio, either. No abnormality of any organ was found during histopathological examination. It is concluded that short-term ingestion of chitooligomers is of non-toxicity.

Calcium interacts with antifreeze proteins and chitinase from cold-acclimated winter rye

During cold acclimation, winter rye (Secale cereale) plants accumulate pathogenesis-related proteins that are also antifreeze proteins (AFPs) because they adsorb onto ice and inhibit its growth. Although they promote winter survival in planta, these dual-function AFPs proteins lose activity when stored at subzero temperatures in vitro, so we examined their stability in solutions containing CaCl2, MgCl2, or NaCl. Antifreeze activity was unaffected by salts before freezing, but decreased after freezing and thawing in CaCl2 and was recovered by adding a chelator. Ca2+ enhanced chitinase activity 3- to 5-fold in unfrozen samples, although hydrolytic activity also decreased after freezing and thawing in CaCl2. Native PAGE, circular dichroism, and Trp fluorescence experiments showed that the AFPs partially unfold after freezing and thawing, but they fold more compactly or aggregate in CaCl2. Ruthenium red, which binds to Ca(2+)-binding sites, readily stained AFPs in the absence of Ca2+, but less stain was visible after freezing and thawing AFPs in CaCl2. We conclude that the structure of AFPs changes during freezing and thawing, creating new Ca(2+)-binding sites. Once Ca2+ binds to those sites, antifreeze activity, chitinase activity and ruthenium red binding are all inhibited. Because free Ca2+ concentrations are typically low in the apoplast, antifreeze activity is probably stable to freezing and thawing in planta. Ca2+ may regulate chitinase activity if concentrations are increased locally by release from pectin or interaction with Ca(2+)-binding proteins. Furthermore, antifreeze activity can be easily maintained in vitro by including a chelator during frozen storage.

Purification and Characterization of an Antifungal Chitinase in Jelly Fig (Ficus awkeotsang) Achenes

A method was developed to purify a 30-kDa protein from jelly fig (Ficus awkeotsang) pericarp, including preparation of jelly curd from achenes, extraction of proteins from the curd, and isolation of the 30-kDa protein by anion-exchanger and gel filtration. Chitinase activity was detected in the purified 30-kDa protein by activity staining in both non-denaturing gel electrophoresis and SDS-PAGE. Isoelectrofocusing showed that the isoelectric point of the 30-kDa protein was lower than pH 3.5. The K(m), k(cat), optimal pH and temperature of this putative chitinase were determined to be 0.076 mM, 0.089 s(-1), pH 4, and 60 degrees C, respectively. The purified 30-kDa protein was thermostable (retaining activity up to 65 degrees C for several hours) and could be stored at 4 degrees C for a year without apparent loss of chitinase activity. Antifungal activity of this putative chitinase was measured in terms of inhibition of Colletotrichum gloeosporioides spore germination.