Displaying publications 1 - 20 of 98 in total

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  1. Fulltext Evaluation of Aqueous Biphasic Electrophoresis System Based on Halide-Free Ionic Liquids for Direct Recovery of Keratinase
    Kee PE, Yim HS, Kondo A, Lan JC, Ng HS
    Mar Drugs, 2021 Aug 17;19(8).
    PMID: 34436302 DOI: 10.3390/md19080463
    Aqueous biphasic electrophoresis system (ABES) incorporates electric fields into the biphasic system to separate the target biomolecules from crude feedstock. Ionic liquid (IL) is regarded as an excellent candidate as the phase-forming components for ABES because of the great electrical conductivity, which can promote the electromigration of biomolecules in ABES, and thereby enhances the separation efficiency of the target biomolecules from crude feedstock. The application of electric fields to the conventional biphasic system expedites the phase settling time of the biphasic system, which eases the subsequent scaling-up steps and reduces the overall processing time of the recovery process. Alkyl sulphate-based IL is a green and economical halide-free surfactant when compared to the other halide-containing IL. The feasibility of halide-free IL-based ABES to recover Kytococcus sedentarius TWHK01 keratinase was studied. Optimum partition coefficient (Ke = 7.53 ± 0.35) and yield (YT = 80.36% ± 0.71) were recorded with IL-ABES comprised of 15.0% (w/w) [EMIM][ESO4], 20.0% (w/w) sodium carbonate and 15% (w/w) crude feedstock. Selectivity (S) of 5.75 ± 0.27 was obtained with the IL-ABES operated at operation time of 5 min with 10 V voltage supplied. Halide-free IL is proven to be a potential phase-forming component of IL-ABES for large-scale recovery of keratinase.
    Matched MeSH terms: Peptide Hydrolases/chemistry*
  2. Fulltext Biotechnological Aspects and Perspective of Microbial Keratinase Production
    Gopinath SC, Anbu P, Lakshmipriya T, Tang TH, Chen Y, Hashim U, et al.
    Biomed Res Int, 2015;2015:140726.
    PMID: 26180780 DOI: 10.1155/2015/140726
    Keratinases are proteolytic enzymes predominantly active when keratin substrates are available that attack disulfide bridges in the keratin to convert them from complex to simplified forms. Keratinases are essential in preparation of animal nutrients, protein supplements, leather manufacture, textile processing, detergent formulation, feather meal processing for feed and fertilizer, the pharmaceutical and biomedical industries, and waste management. Accordingly, it is necessary to develop a method for continuous production of keratinase from reliable sources that can be easily managed. Microbial keratinase is less expensive than conventionally produced keratinase and can be obtained from fungi, bacteria, and actinomycetes. In this overview, the expansion of information about microbial keratinases and important considerations in keratinase production are discussed.
    Matched MeSH terms: Peptide Hydrolases/chemistry*
  3. Fulltext Draft Genome Sequence of Lysinibacillus sp. Strain A1, Isolated from Malaysian Tropical Soil
    Chan KG, Chen JW, Chang CY, Yin WF, Chan XY
    Genome Announc, 2015;3(2).
    PMID: 25814592 DOI: 10.1128/genomeA.00095-15
    In this work, we describe the genome of Lysinibacillus sp. strain A1, which was isolated from tropical soil. Analysis of its genome sequence shows the presence of a gene encoding for a putative peptidase responsible for nitrogen compounds.
    Matched MeSH terms: Peptide Hydrolases
  4. Strategies to improve the physicochemical properties of peptide-based drugs
    Lee MF, Poh CL
    Pharm Res, 2023 Mar;40(3):617-632.
    PMID: 36869247 DOI: 10.1007/s11095-023-03486-0
    Peptides are a rapid-growing class of therapeutics with unique and desirable physicochemical properties. Due to disadvantages such as low membrane permeability and susceptibility to proteolytic degradation, peptide-based drugs have limited bioavailability, a short half-life, and rapid in vivo elimination. Various strategies can be applied to improve the physicochemical properties of peptide-based drugs to overcome limitations such as limited tissue residence time, metabolic instability, and low permeability. Applied strategies including backbone modifications, side chain modifications, conjugation with polymers, modification of peptide termini, fusion to albumin, conjugation with the Fc portion of antibodies, cyclization, stapled peptides, pseudopeptides, cell-penetrating peptide conjugates, conjugation with lipids, and encapsulation in nanocarriers are discussed.
    Matched MeSH terms: Peptide Hydrolases
  5. Fulltext Extraction of non-starch lipid from protease-treated wheat flour
    Abdul Manan SF, Li J, Hsieh CF, Faubion J, Shi YC
    J Sci Food Agric, 2022 Mar 30;102(5):2172-2178.
    PMID: 34498279 DOI: 10.1002/jsfa.11523
    BACKGROUND: Lipids account for 2.0-2.5% of wheat flour by dry weight and affect properties and quality of cereal foods. A new method was developed to extract non-starch lipids from wheat flour. Wheat flour was first hydrolyzed with a protease and followed by extraction of non-starch lipids by water-saturated butanol (WSB).

    RESULT: Protein hydrolysis by protease followed by extraction of non-starch lipids with WSB increased yield to 1.9 ± 0.3% from 1.0 ± 0.1% with no protease treatment. The lipid profile showed a significant increase in phospholipid compounds extracted with protease hydrolysis (5.9 ± 0.8 nmol·g-1 ) versus without enzymatic treatment (2.4 ± 1.3 nmol g-1 ).

    CONCLUSION: Improved lipid extraction yield and phospholipid compounds following protease-assisted extraction method provided additional insight towards the understanding of protein-lipid interaction in wheat flour. The new protease-assisted extraction method may be applied to analyzing non-starch lipids in other types of wheat flours and other cereal flours. © 2021 Society of Chemical Industry.

    Matched MeSH terms: Peptide Hydrolases
  6. Phytochemical profiling of the essential oils from three Curcuma species and their in vitro and in silico dengue protease inhibition activity
    Jani NA, Maarof NI, Zahari MMFM, Jamil M, Zakaria II, Mohamad Zobir SZ, et al.
    Nat Prod Res, 2024 Mar;38(6):926-932.
    PMID: 37144399 DOI: 10.1080/14786419.2023.2208256
    The chemical compositions, in vitro and in silico anti-dengue activity of the essential oils of the rhizomes of Curcuma longa Linn., C. aeruginosa Roxb., and C. xanthorrhiza Roxb. had been investigated. The C. longa oil was mainly composed of ar-turmerone (54.0%) and curlone (17.7%), while the C. aeruginosa oil was rich in curzerenone (23.4%), 1,8-cineole (21.2%), and camphor (7.1%). Xanthorrhizol (21.6%), β-curcumene (19.5%), ar-curcumene (14.2%), and camphor (9.2%) were the major compounds in the C. xanthorrhiza oil. Among the oils, the C. longa oil was found to be the most active NSB-NS3 protease inhibitor (IC50 1.98 μg/mL). PLS biplot disclosed that the essential oils were classified into three separated clusters based on their characteristic chemical compositions, with C. longa positioned closest to the in vitro anti-dengue activity. Four compounds from the C. longa oil have both hydrogen and hydrophobic bonds that could be responsible for the DENV-2 NS2B-NS3 inhibitory effect.
    Matched MeSH terms: Peptide Hydrolases
  7. Molecular factors in human implantation: adhesion molecules, proteases and cytokines
    Lim KJ
    Malays J Pathol, 2003 Jun;25(1):1-13.
    PMID: 16196373
    Successful human reproduction remains an enigma, but this is slowly changing in the current era of expanding scientific knowledge. The discovery of various molecular factors such as adhesion molecules, proteases and cytokines have in recent years been at the forefront of medical research. The growing importance of immunology in particular has led to novel new immuno-modulatory therapies and increasing research into this new aspect of reproductive immunology may well prove to be the most important breakthrough in understanding the fundamentals of human reproduction. Implantation represents the first step in the complex interactions and processes involved in foetal-maternal interaction, which continues throughout pregnancy gestation and culminates in the birth of an infant. It is therefore vital that we understand the myriad processes controlling implantation in order to build a firm foundation for exploring reproductive immunology research in the new millennium. This review brings together and presents an overview of the potential roles of currently known molecular factors such as adhesion molecules, proteases, cytokines and its interaction with the maternal immune response, incorporating the findings of previous published research performed by the author on cytokines and reproductive immunology.
    Matched MeSH terms: Peptide Hydrolases/metabolism*
  8. Antioxidant and functional properties of protein hydrolysates obtained from squid pen chitosan extraction effluent
    Shavandi A, Hu Z, Teh S, Zhao J, Carne A, Bekhit A, et al.
    Food Chem, 2017 Jul 15;227:194-201.
    PMID: 28274422 DOI: 10.1016/j.foodchem.2017.01.099
    Squid pens were subjected to alkali hydrolysis to extract chitin and chitosan. Proteins present in the alkaline extraction wastewater were recovered at pH 3, 4, 5 and 6, and were subjected to hydrolysis by trypsin, pepsin and a bacterial protease called HT for 1, 2, 4 and 24h. Hydrolysis of the extracted proteins with either trypsin or HT generated more antioxidant activity than hydrolysis with pepsin. Higher ACE-inhibitory activity was generated in the trypsin and pepsin hydrolysates than in the HT hydrolysate. Squid pen protein recovered from chitosan processing waste alkaline solution can be a potential source of bioactive peptides for addition to foods. The antioxidant and ACE-inhibitory activities of the extracted proteins were initially low and increased upon incubation with the proteases. Pepsin generated significantly lower (P<0.05) antioxidant activities compared to trypsin and HT, while trypsin and pepsin hydrolysates exhibited higher ACE-inhibitory activity than HT (P<0.05).
    Matched MeSH terms: Peptide Hydrolases/metabolism
  9. Effects of pristine polyvinyl chloride fragments on whole body histology and protease activity in silver barb Barbodes gonionotus fry
    Romano N, Ashikin M, Teh JC, Syukri F, Karami A
    Environ Pollut, 2018 Jun;237:1106-1111.
    PMID: 29157968 DOI: 10.1016/j.envpol.2017.11.040
    Silver barb Barbodes gonionotus fry were exposed to polyvinyl chloride (PVC) fragments at increasing concentrations of 0.2, 0.5 and 1.0 mg/L for 96 h, following which whole body histological evaluation and analysis of the digestive enzymes trypsin and chymotrypsin were performed. Whole body trypsin and chymotrypsin activities increased significantly in fish exposed to 0.5 and 1.0 mg/L PVC as compared those exposed to zero or 0.2 mg/L PVC. In fish exposed to all tested concentrations, PVCs were observed in both the proximal and distal intestine, and fish exposed to 0.5-1.0 and 1.0 mg/L PVC, respectively, and these particles were associated with localized thickening of the mucosal epithelium. No tissue damage was evident in any other internal organs or gills. This lack of damage may be attributed to the absence of contaminants associated with the PVC fragments and their relatively smooth surface. The increased whole body trypsin and chymotrypsin activities may indicate an attempt to enhance digestion to compensate for epithelial thickening of the intestine and/or to digest the plastics.
    Matched MeSH terms: Peptide Hydrolases/metabolism*
  10. Fulltext Purification and characterization of alkaline-thermostable protease enzyme from Pitaya (Hylocereus polyrhizus) waste: a potential low cost of the enzyme
    Amid M, Manap MY, Zohdi NK
    Biomed Res Int, 2014;2014:259238.
    PMID: 25328883 DOI: 10.1155/2014/259238
    The thermoalkaline protease enzyme from pitaya (Hylocereus polyrhizus) waste was purified by a factor of 221.2 with 71.3% recovery using ammonium sulphate precipitation, gel filtration, and cation exchange chromatography. Gel filtration chromatography together with sodium dodecyl sulphate gel electrophoresis (SDS-PAGE) revealed that the enzyme is monomeric with a molecular weight of 26.7 kDa. The apparent K m and V max of the protease were 2.8 mg/mL and 31.20 u/min, respectively. The optimum pH and temperature were 8.0 and 70°C. The enzyme was highly active and stable over a wide pH range (from pH 3.0 to pH 11.0 with the optimum activity at pH 8.0). The protease has broad specificity toward azocasein, casein, hemoglobin, and gelatine. Activity of the enzyme was inhibited by Fe(2+) and Zn(2+), while protease activity was increased in the presence of Ca(2+) and Mg(2+) and Cu(2+) by factors of 125%, 110%, and 105%, respectively. The alkaline protease showed extreme stability toward surfactants and oxidizing agent. The purified protease exhibited extreme stability in the presence of organic solvents and inhibitors. In addition, the enzyme was relativity stable toward organic solvents and chelating agents, such as ethylenediaminetetraacetic acid (EDTA). The enzyme, derived from pitaya peel, possesses unique characteristics and could be used in various industrial and biotechnological applications.
    Matched MeSH terms: Peptide Hydrolases/classification; Peptide Hydrolases/isolation & purification*; Peptide Hydrolases/chemistry*
  11. Physical factors affecting the production of organic solvent-tolerant protease by Pseudomonas aeruginosa strain K
    Rahman RN, Geok LP, Basri M, Salleh AB
    Bioresour Technol, 2005 Mar;96(4):429-36.
    PMID: 15491823
    The physical factors affecting the production of an organic solvent-tolerant protease from Pseudomonas aeruginosa strain K was investigated. Growth and protease production were detected from 37 to 45 degrees C with 37 degrees C being the optimum temperature for P. aeruginosa. Maximum enzyme activity was achieved at static conditions with 4.0% (v/v) inoculum. Shifting the culture from stationary to shaking condition decreased the protease production (6.0-10.0% v/v). Extracellular organic solvent-tolerant protease was detected over a broad pH range from 6.0 to 9.0. However, the highest yield of protease was observed at pH 7.0. Neutral media increased the protease production compared to acidic or alkaline media.
    Matched MeSH terms: Peptide Hydrolases/biosynthesis*; Peptide Hydrolases/classification; Peptide Hydrolases/chemistry*
  12. Fulltext Effects of precipitation methods on the properties of protease extracted from starfruit (Averrhoa carambola L.) of different maturity index
    Normah, Ismail, Ezzana Zuraini, Zainuddin
    Scientific Research Journal, 2015;12(1):1-12.
    MyJurnal
    Proteases were extracted from starfruit at maturity Index 2 (unripe, light green) and Index 7 (very ripe, orange) and partially purified using acetone and 40% ammonium sulfate precipitations. Higher yield and proteolytic activity were observed for proteases purified using acetone than 40% ammonium sulfate. As for maturity index, yield and protein concentration of proteases from Index 2 were higher than those from Index 7. SDS-PAGE result showed intense bands for acetone proteases while a distinct band at 50 kDa was observed in all the proteases. Enzyme activity decreased during the seven days storage at 4°C with minimum relative activity of 70% achieved for acetone proteases at day seven. This study suggested that acetone precipitation is more effective method for purifying starfruit protease based on the yield and proteolytic activity compared to using 40% ammonium sulphate precipitation. In order to obtain higher protein concentration and proteolytic activity, starfruit at the unripe stage, Index 2 is a better raw material than Index 7 to be used for protease production.
    Matched MeSH terms: Peptide Hydrolases
  13. Fulltext Extraction and partial purification of protease from bilimbi
    Normah Ismail, Nur’ Ain Mohamad Kharoe
    Scientific Research Journal, 2013;10(2):0-0.
    MyJurnal
    Unripe and ripe bilimbi (Averrhoa bilimbi. L) were ground and the extracted juices were partially purified by ammonium sulfate precipitation at the concentrations of 40 and 60% (w/v). The collected proteases were analysed for pH, temperature stability, storage stability, molecular weight distribution, protein concentration and protein content. Protein content of bilimbi fruit was 0.89 g. Protease activity of both the unripe and ripe fruit were optimum at pH 4 and 40ºC when the juice were purified at 40 and 60% ammonium sulfate precipitation. A decreased in protease activity was observed during the seven days of storage at 4°C. Molecular weight distribution indicated that the proteases protein bands fall between 10 to 220 kDa. Protein bands were observed at 25, 50 and 160 kDa in both the unripe and ripe bilimbi proteases purified with 40% ammonium sulfate, however, the bands were more intense in those from unripe bilimbi. No protein bands were seen in proteases purified with 60% ammonium sulfate. Protein concentration was higher for proteases extracted with 40% ammonium sulfate at both ripening stages. Thus, purification using 40% ammonium sulfate precipitation could be a successful method to partially purify proteases from bilimbi especially from the unripe stage.
    Matched MeSH terms: Peptide Hydrolases
  14. Protease activity is maintained in Nepenthes ampullaria digestive fluids depleted of endogenous proteins with compositional changes
    Ravee R, Baharin A, Cho WT, Ting TY, Goh HH
    Physiol Plant, 2021 Dec;173(4):1967-1978.
    PMID: 34455610 DOI: 10.1111/ppl.13540
    Nepenthes ampullaria is a unique carnivorous tropical pitcher plant with the detritivorous capability of sequestering nutrients from leaf litter apart from being insectivorous. The changes in the protein composition and protease activity of its pitcher fluids during the early opening of pitchers (D0 and D3C) were investigated via a proteomics approach and a controlled protein depletion experiment (D3L). A total of 193 proteins were identified. Common proteins such as pathogenesis-related protein, proteases (Nep [EC:3.4.23.12], SCP [EC:3.4.16.-]), peroxidase [EC:1.11.1.7], GDSL esterase/lipase [EC:3.1.1.-], and purple acid phosphatase [EC:3.1.3.2] were found in high abundance in the D0 pitchers and were replenished in D3L samples. This reflects their importance for biological processes upon pitcher opening. Meanwhile, prey-inducible chitinases [EC:3.2.1.14] were found in D0 but not in D3C and D3L samples, which suggests their degradation in the absence of prey. Protease activity assays demonstrated the replenishment of proteases in D3L with similar levels of proteolytic activities to that of D3C samples. This supports a feedback mechanism and signaling in the molecular regulation of endogenous protein secretion, turnover, and activity in Nepenthes pitcher fluids. Furthermore, we also discovered several new enzymes (XTH [EC:2.4.1.207], PAE [EC:3.1.1.98]) with possible functions in cell wall degradation that could contribute to the detritivory habit of N. ampullaria.
    Matched MeSH terms: Peptide Hydrolases
  15. Fulltext Amoebic forms of Blastocystis spp. - evidence for a pathogenic role
    Rajamanikam A, Govind SK
    Parasit Vectors, 2013;6(1):295.
    PMID: 24499467 DOI: 10.1186/1756-3305-6-295
    Blastocystis spp. are one of the most prevalent parasites isolated from patients suffering from diarrhea, flatulence, constipation and vomiting. It's pathogenicity and pathophysiology remains controversial to date. Protease activity and amoebic forms have been reported previously in symptomatic isolates but there has been no conclusive evidence provided to correlate the protease activity and any specific life cycle stage of the parasite thus far.
    Matched MeSH terms: Peptide Hydrolases/secretion*; Peptide Hydrolases/chemistry
  16. Docking of noncompetitive inhibitors into dengue virus type 2 protease: understanding the interactions with allosteric binding sites
    Othman R, Kiat TS, Khalid N, Yusof R, Newhouse EI, Newhouse JS, et al.
    J Chem Inf Model, 2008 Aug;48(8):1582-91.
    PMID: 18656912 DOI: 10.1021/ci700388k
    A group of flavanones and their chalcones, isolated from Boesenbergia rotunda L., were previously reported to show varying degrees of noncompetitive inhibitory activities toward Dengue virus type 2 (Den2) protease. Results obtained from automated docking studies are in agreement with experimental data in which the ligands were shown to bind to sites other than the active site of the protease. The calculated K(i) values are very small, indicating that the ligands bind quite well to the allosteric binding site. Greater inhibition by pinostrobin, compared to the other compounds, can be explained by H-bonding interaction with the backbone carbonyl of Lys74, which is bonded to Asp75 (one of the catalytic triad residues). In addition, structure-activity relationship analysis yields structural information that may be useful for designing more effective therapeutic drugs against dengue virus infections.
    Matched MeSH terms: Peptide Hydrolases/metabolism*; Peptide Hydrolases/chemistry*
  17. Draft genome sequence of Vitellibacter vladivostokensis KMM 3516(T): a protease-producing bacterium
    Thevarajoo S, Selvaratnam C, Chan KG, Goh KM, Chong CS
    Mar Genomics, 2015 Oct;23:49-50.
    PMID: 25957696 DOI: 10.1016/j.margen.2015.04.009
    Type strain Vitellibacter vladivostokensis KMM 3516(T) (=NBRC 16718(T)) belongs to the phylum Cytophaga-Flavobacterium-Bacteroides. To date, no genomes of the Vitellibacter spp. have been reported, and their metabolic pathways are unknown. This study reports the draft genome sequence of V. vladivostokensis. Moreover, mining of genes associated with proteolytic enzymes was performed to provide insights for further enzyme characterization.
    Matched MeSH terms: Peptide Hydrolases/genetics; Peptide Hydrolases/metabolism*
  18. Actions of three clostridial IgA proteases on distinct forms of immunoglobulin A molecules
    Hashim OH, Hassan H
    Immunology, 1991 Jun;73(2):235-8.
    PMID: 2071167
    Three bacterial species of Clostridium (septicum, tertium and sporogenes) were identified to produce extracellular proteases cleaving IgA to Fab and Fc fragments, as demonstrated by SDS-PAGE and immunoelectrophoretic procedures. These enzymes acted on monometric IgA1 paraproteins and normal serum IgA1 but had no activity on IgA2 paraproteins and intact secretory IgA1 from human colostrum. Their action on polyclonal serum IgA1 suggested the absence of neutralizing anti-clostridial IgA protease activity. Although the enzymes were shown not to act on secretory IgA1, they were, however, able to digest free alpha-heavy chains of the dimeric IgA molecules. Susceptibility of the alpha-heavy chain to the proteases was more likely due to the change to a more accessible conformation than because of the absence of neutralizing anti-enzymic activity.
    Matched MeSH terms: Peptide Hydrolases/metabolism; Peptide Hydrolases/physiology*
  19. Simultaneous lactic acidification and coagulation by using recombinant Lactococcus lactis strain
    Raftari M, Ghafourian S, Abu Bakar F
    J Appl Microbiol, 2017 Apr;122(4):1009-1019.
    PMID: 28028882 DOI: 10.1111/jam.13388
    AIMS: This study was an attempt to create a novel milk clotting procedure using a recombinant bacterium capable of milk coagulation.

    METHODS AND RESULTS: The Rhizomucor pusillus proteinase (RPP) gene was sub-cloned into a pALF expression vector. The recombinant pALF-RPP vector was then electro-transferred into Lactococcus lactis. Finally, the milk coagulation ability of recombinant L. lactis carrying a RPP gene was evaluated. Nucleotide sequencing of DNA insertion from the clone revealed that the RPP activity corresponded to an open reading frame consisting of 1218 bp coding for a 43·45 kDa RPP protein. The RPP protein assay results indicated that the highest RPP enzyme expression with 870 Soxhlet units (SU) per ml and 7914 SU/OD were obtained for cultures which were incubated at pH 5·5 and 30°C. Interestingly, milk coagulation was observed after 205 min of inoculating milk with recombinant L. lactis carrying the RPP gene.

    CONCLUSION: The recombinant L. lactis carrying RPP gene has the ability to function as a starter culture for acidifying and subsequently coagulating milk by producing RPP as a milk coagulant agent.

    SIGNIFICANCE AND IMPACT OF THE STUDY: Creating a recombinant starter culture bacterium that is able to coagulate milk. It is significant because the recombinant L. lactis has the ability to work as a starter culture and milk coagulation agent.

    Matched MeSH terms: Peptide Hydrolases/genetics*; Peptide Hydrolases/metabolism
  20. ProLysED: an integrated database and meta-server of bacterial protease systems
    Firdaus Raih M, Ahmad HA, Sharum MY, Azizi N, Mohamed R
    Appl. Bioinformatics, 2005;4(2):147-50.
    PMID: 16128617
    Bacterial proteases are an important group of enzymes that have very diverse biochemical and cellular functions. Proteases from prokaryotic sources also have a wide range of uses, either in medicine as pathogenic factors or in industry and therapeutics. ProLysED (Prokaryotic Lysis Enzymes Database), our meta-server integrated database of bacterial proteases, is a useful, albeit very niche, resource. The features include protease classification browsing and searching, organism-specific protease browsing, molecular information and visualisation of protease structures from the Protein Data Bank (PDB) as well as predicted protease structures.
    Matched MeSH terms: Peptide Hydrolases/classification; Peptide Hydrolases/chemistry*
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