Displaying publications 21 - 40 of 223 in total

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  1. 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
  2. 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
  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. Fulltext An S188V mutation alters substrate specificity of non-stereospecific α-haloalkanoic acid dehalogenase E (DehE)
    Hamid AA, Hamid TH, Wahab RA, Omar MS, Huyop F
    PLoS One, 2015;10(3):e0121687.
    PMID: 25816329 DOI: 10.1371/journal.pone.0121687
    The non-stereospecific α-haloalkanoic acid dehalogenase E (DehE) degrades many halogenated compounds but is ineffective against β-halogenated compounds such as 3-chloropropionic acid (3CP). Using molecular dynamics (MD) simulations and site-directed mutagenesis we show here that introducing the mutation S188V into DehE improves substrate specificity towards 3CP. MD simulations showed that residues W34, F37, and S188 of DehE were crucial for substrate binding. DehE showed strong binding ability for D-2-chloropropionic acid (D-2CP) and L-2-chloropropionic acid (L-2CP) but less affinity for 3CP. This reduced affinity was attributed to weak hydrogen bonding between 3CP and residue S188, as the carboxylate of 3CP forms rapidly interconverting hydrogen bonds with the backbone amide and side chain hydroxyl group of S188. By replacing S188 with a valine residue, we reduced the inter-molecular distance and stabilised bonding of the carboxylate of 3CP to hydrogens of the substrate-binding residues. Therefore, the S188V can act on 3CP, although its affinity is less strong than for D-2CP and L-2CP as assessed by Km. This successful alteration of DehE substrate specificity may promote the application of protein engineering strategies to other dehalogenases, thereby generating valuable tools for future bioremediation technologies.
    Matched MeSH terms: Hydrolases/genetics*; Hydrolases/metabolism; Hydrolases/chemistry*
  5. Identification of functional residues essential for dehalogenation by the non-stereospecific α-haloalkanoic acid dehalogenase from Rhizobium sp. RC1
    Hamid AA, Hamid TH, Wahab RA, Huyop F
    J Basic Microbiol, 2015 Mar;55(3):324-30.
    PMID: 25727054 DOI: 10.1002/jobm.201570031
    The non-stereospecific α-haloalkanoic acid dehalogenase DehE from Rhizobium sp. RC1 catalyzes the removal of the halide from α-haloalkanoic acid D,L-stereoisomers and, by doing so, converts them into hydroxyalkanoic acid L,D-stereoisomers, respectively. DehE has been extensively studied to determine its potential to act as a bioremediation agent, but its structure/function relationship has not been characterized. For this study, we explored the functional relevance of several putative active-site amino acids by site-specific mutagenesis. Ten active-site residues were mutated individually, and the dehalogenase activity of each of the 10 resulting mutants in soluble cell lysates against D- and L-2-chloropropionic acid was assessed. Interestingly, the mutants W34→A,F37→A, and S188→A had diminished activity, suggesting that these residues are functionally relevant. Notably, the D189→N mutant had no activity, which strongly implies that it is a catalytically important residue. Given our data, we propose a dehalogenation mechanism for DehE, which is the same as that suggested for other non-stereospecific α-haloalkanoic acid dehalogenases. To the best of our knowledge, this is the first report detailing a functional aspect for DehE, and our results could help pave the way for the bioengineering of haloalkanoic acid dehalogenases with improved catalytic properties.
    Matched MeSH terms: Hydrolases/genetics; Hydrolases/metabolism*; Hydrolases/chemistry*
  6. Cloning, expression and characterization of a novel cold‑adapted GDSL family esterase from Photobacterium sp. strain J15
    Shakiba MH, Ali MS, Rahman RN, Salleh AB, Leow TC
    Extremophiles, 2016 Jan;20(1):44-55.
    PMID: 26475626 DOI: 10.1007/s00792-015-0796-4
    The gene encoding for a novel cold-adapted enzyme from family II of bacterial classification (GDSL family) was cloned from the genomic DNA of Photobacterium sp. strain J15 in an Escherichia coli system, yielding a recombinant 36 kDa J15 GDSL esterase which was purified in two steps with a final yield and purification of 38.6 and 15.3 respectively. Characterization of the biochemical properties showed the J15 GDSL esterase had maximum activity at 20 °C and pH 8.0, was stable at 10 °C for 3 h and retained 50 % of its activity after a 6 h incubation at 10 °C. The enzyme was activated by Tween-20, -60 and Triton-X100 and inhibited by 1 mM Sodium dodecyl sulphate (SDS), while β-mercaptoethanol and Dithiothreitol (DTT) enhanced activity by 4.3 and 5.4 fold respectively. These results showed the J15 GDSL esterase was a novel cold-adapted enzyme from family II of lipolytic enzymes. A structural model constructed using autotransporter EstA from Pseudomonas aeruginosa as a template revealed the presence of a typical catalytic triad consisting of a serine, aspartate, and histidine which was verified with site directed mutagenesis on active serine.
    Matched MeSH terms: Carboxylic Ester Hydrolases/genetics; Carboxylic Ester Hydrolases/metabolism*; Carboxylic Ester Hydrolases/chemistry
  7. Fulltext Semantic segmentation of urban environments: Leveraging U-Net deep learning model for cityscape image analysis
    Arulananth TS, Kuppusamy PG, Ayyasamy RK, Alhashmi SM, Mahalakshmi M, Vasanth K, et al.
    PLoS One, 2024;19(4):e0300767.
    PMID: 38578733 DOI: 10.1371/journal.pone.0300767
    Semantic segmentation of cityscapes via deep learning is an essential and game-changing research topic that offers a more nuanced comprehension of urban landscapes. Deep learning techniques tackle urban complexity and diversity, which unlocks a broad range of applications. These include urban planning, transportation management, autonomous driving, and smart city efforts. Through rich context and insights, semantic segmentation helps decision-makers and stakeholders make educated decisions for sustainable and effective urban development. This study investigates an in-depth exploration of cityscape image segmentation using the U-Net deep learning model. The proposed U-Net architecture comprises an encoder and decoder structure. The encoder uses convolutional layers and down sampling to extract hierarchical information from input images. Each down sample step reduces spatial dimensions, and increases feature depth, aiding context acquisition. Batch normalization and dropout layers stabilize models and prevent overfitting during encoding. The decoder reconstructs higher-resolution feature maps using "UpSampling2D" layers. Through extensive experimentation and evaluation of the Cityscapes dataset, this study demonstrates the effectiveness of the U-Net model in achieving state-of-the-art results in image segmentation. The results clearly shown that, the proposed model has high accuracy, mean IOU and mean DICE compared to existing models.
    Matched MeSH terms: Hydrolases
  8. 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
  9. Electrophoretic profiles and biological activities: intraspecific variation in the venom of the Malayan pit viper (Calloselasma rhodostoma)
    Daltry JC, Ponnudurai G, Shin CK, Tan NH, Thorpe RS, Wüster W
    Toxicon, 1996 Jan;34(1):67-79.
    PMID: 8835335
    The Malayan pit viper (Calloselasma rhodostoma) is of major clinical significance both as a leading cause of snakebite and as the source of ancrod (Arvin). Although its venom has been extensively studied, the degree to which venom composition varies between individuals is poorly known. We individually analysed the venoms of over 100 C. rhodostoma using isoelectric focusing. In all populations, females produced an intense band that was absent from all males, and significant ontogenetic variation was detected. Principal components analysis of the banding profiles also revealed strong geographic variation, which was significantly congruent with variation in the biological activities of the venom (phosphodiesterase, alkalinephosphoesterase, L-amino acid oxidase, arginine ester hydrolase, 5'-nucleotidase, thrombin-like enzyme, haemorrhagic activity). Studies of captive-bred snakes indicate that the intraspecific variation in venom is genetically inherited rather than environmentally induced. The intraspecific variation in venom composition and biological activity could be of applied importance to snakebite therapy, both in correct diagnosis of the source of envenomation and in the development of a more effective antivenom. Greater attention should be given to the source of C. rhodostoma venom used in research to ensure reproducibility of results.
    Matched MeSH terms: Carboxylic Ester Hydrolases/metabolism; Phosphoric Diester Hydrolases/metabolism; Phosphoric Monoester Hydrolases/metabolism
  10. A comparative study of the biological properties of krait (genus Bungarus) venoms
    Tan NH, Ponnudurai G
    Comp Biochem Physiol C Comp Pharmacol Toxicol, 1990;95(1):105-9.
    PMID: 1971550
    1. The intravenous median lethal doses (LD50), protease, phosphodiesterase, alkaline phosphomonoesterase, L-amino acid oxidase, acetylcholinesterase, phospholipase A, 5'-nucleotidase, hyauronidase and anticoagulant activities of fourteen samples of venoms from the four common species of krait (Bungarus caeruleus, Bungarus candidus, Bungarus multicinctus and Bungarus fasciatus) were examined. 2. The results indicate that even though there are individual variations in the biological properties of the krait venoms, interspecific differences in the properties can be used for differentiation of the venoms from the four species of Bungarus. Particularly useful for this purpose are the LD50's and the contents of 5'-nucleotidase and hyaluronidase of the venoms.
    Matched MeSH terms: Carboxylic Ester Hydrolases/metabolism; Peptide Hydrolases/metabolism; Phosphoric Diester Hydrolases/metabolism
  11. Fulltext Improving the Efficiency of New Automatic Dishwashing Detergent Formulation by Addition of Thermostable Lipase, Protease and Amylase
    Naganthran A, Masomian M, Rahman RNZRA, Ali MSM, Nooh HM
    Molecules, 2017 Sep 19;22(9).
    PMID: 28925972 DOI: 10.3390/molecules22091577
    The use of T1 lipase in automatic dishwashing detergent (ADD) is well established, but efficiency in hard water is very low. A new enzymatic environmentally-friendly dishwashing was formulated to be efficient in both soft and hard water. Thermostable enzymes such as T1 lipase from Geobacillus strain T1, Rand protease from Bacillussubtilis strain Rand, and Maltogenic amylase from Geobacillus sp. SK70 were produced and evaluated for an automatic dishwashing detergent formulation. The components of the new ADD were optimized for compatibility with these three enzymes. In compatibility tests of the enzymes with different components, several criteria were considered. The enzymes were mostly stable in non-ionic surfactants, especially polyhydric alcohols, Glucopon UP 600, and in a mixture of sodium carbonate and glycine (30:70) buffer at a pH of 9.25. Sodium polyacrylate and sodium citrate were used in the ADD formulation as a dispersing agent and a builder, respectively. Dishwashing performance of the formulated ADDs was evaluated in terms of percent of soil removed using the Leenert's Improved Detergency Tester. The results showed that the combination of different hydrolysis enzymes could improve the washing efficiency of formulated ADD compared to the commercial ADD "Finish" at 40 and 50 C.
    Matched MeSH terms: Glycoside Hydrolases; Peptide Hydrolases
  12. 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*
  13. Synthesis, α-glycosidase inhibitory potential and molecular docking study of benzimidazole derivatives
    Taha M, Rahim F, Zaman K, Selvaraj M, Uddin N, Farooq RK, et al.
    Bioorg Chem, 2020 01;95:103555.
    PMID: 31911306 DOI: 10.1016/j.bioorg.2019.103555
    A series of twenty-six analogs of benzimidazole based oxadiazole have been synthesized and evaluated against alpha-glycosidase enzyme. Most the analogs showed excellent to good inhibitory potential. Among the screened analogs, analog 1, 2, 3 and 14 with IC50 values 4.6 ± 0.1, 9.50 ± 0.3, 2.6 ± 0.1 and 9.30 ± 0.4 µM respectively showedexcellent inhibitory potential than reference drug acarbose (IC50 = 38.45 ± 0.80 µM). Some of the analogs like 19, 21, 22 and 23 with methyl and methoxy substituent on phenyl ring show hydrophobic interaction and were found with no inhibitory potential. The binding interactions between synthesized analogs and ligands protein were confirmed through molecular docking study. Various spectroscopic techniques like 1H NMR, 13C NMR, and EI-MS were used for characterization of all synthesized analogs. These derivatives were synthesized by simple mode of synthesis like heterocyclic ring formation.
    Matched MeSH terms: Glycoside Hydrolases/antagonists & inhibitors*
  14. Characterization of crude 5'-phosphodiesterase from germinated adzuki (Vigna angularis L.) beans
    Pui LP, Mohammed AS, Ghazali HM
    Acta Sci Pol Technol Aliment, 2020 9 27;19(3):319-331.
    PMID: 32978914 DOI: 10.17306/J.AFS.0804
    BACKGROUND: 5'-Phosphodiesterase (5'-PDE) is an enzyme that hydrolyzes RNA to form 5'-inosine monophosphate (5'-IMP) and 5'-guanosine monophosphate (5'-GMP). These 5'-nucleotides can function as flavor enhancers. Adzuki beans (Vigna angularis L.) are found to be high in 5'-PDE.

    METHODS: 5'-phosphodiesterase (5'-PDE) enzyme was characterized from adzuki beans, in which the optimum pH and temperature were determined. In addition, the stability of 5'-PDE was assessed at different pH and temperature. The effects of cations and EDTA were evaluated to characterize the 5'-PDE enzymes further.

    RESULTS: The alkaline 5'-phosphodiesterase has an optimum pH of 8.5. This enzyme is also thermostable, with an optimum temperature of 80°C. The stability in terms of temperature and pH was also determined, and was found to be stable in the pH range of 7.0-8.5. This enzyme was found to retain more than 80% of its activity for 4 days at 60 and 65°C. In addition, the effects of 14 different metal ions, 4 types of detergents and ethylenediaminetetraacetic acid (EDTA) on 5'-PDE were studied. Ca2+, K+, Mg2+ and Li+ activated 5'-PDE while Na+, Zn2+, Ni+, Hg+, Cu2+, Pb2+, Fe2+, Al3+, Ba2+ and Co2+ were inhibitory. EDTA, Triton X-100 and sodium dodecyl sulfate (SDS) were strong inhibitors of 5'-PDE, while Tween 80 and Tween 20 were slightly inhibitory. The effects of cations and EDTA suggest that 5'-PDE from adzuki beans is a metalloenzyme.

    CONCLUSIONS: Although 5'-PDE from adzuki beans has a high temperature optimum of 80°C, the enzyme is more stable at 60°C, and different cations affected the activity of the enzyme differently.

    Matched MeSH terms: Phosphoric Diester Hydrolases/chemistry*
  15. Effects of metsulphuron-methyl on amylase, invertase and xylanase activities in two soil types
    Ismail BS, Ampong N, Omar O
    Microbios, 2000;103(405):73-83.
    PMID: 11092189
    Effects of metsulphuron-methyl on the activities of amylase, invertase and xylanase in loamy sand and clay were evaluated for up to 28 days under laboratory conditions. Metsulphuron-methyl at 1.0 microg/g caused a significant reduction in amylase, invertase and xylanase activities for the entire period of study, especially at 28 days incubation in both soils. The lowest activities of the three enzymes were observed in the presence of 5.0 microg/g at 28 days incubation.
    Matched MeSH terms: Glycoside Hydrolases/metabolism*
  16. 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
  17. Fulltext Structure prediction, molecular dynamics simulation and docking studies of D-specific dehalogenase from Rhizobium sp. RC1
    Sudi IY, Wong EL, Joyce-Tan KH, Shamsir MS, Jamaluddin H, Huyop F
    Int J Mol Sci, 2012;13(12):15724-54.
    PMID: 23443090 DOI: 10.3390/ijms131215724
    Currently, there is no three-dimensional structure of D-specific dehalogenase (DehD) in the protein database. We modeled DehD using ab initio technique, performed molecular dynamics (MD) simulation and docking of D-2-chloropropionate (D-2CP), D-2-bromopropionate (D-2BP), monochloroacetate (MCA), monobromoacetate (MBA), 2,2-dichloropropionate (2,2-DCP), d,l-2,3-dichloropropionate (d,l-2,3-DCP), and 3-chloropropionate (3-CP) into the DehD active site. The sequences of DehD and D-2-haloacid dehalogenase (HadD) from Pseudomonas putida AJ1 have 15% sequence similarity. The model had 80% of the amino acid residues in the most favored region when compared to the crystal structure of DehI from Pseudomonas putida PP3. Docking analysis revealed that Arg107, Arg134 and Tyr135 interacted with D-2CP, and Glu20 activated the water molecule for hydrolytic dehalogenation. Single residue substitutions at 25-30 °C showed that polar residues of DehD were stable when substituted with nonpolar residues and showed a decrease in activity within the same temperature range. The molecular dynamics simulation of DehD and its variants showed that in R134A variant, Arg107 interacted with D-2CP, while in Y135A, Gln221 and Arg231 interacted with D-2CP. It is our emphatic belief that the new model will be useful for the rational design of DehDs with enhanced potentials.
    Matched MeSH terms: Hydrolases/chemistry*
  18. 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*
  19. Papaya beta-galactosidase/galactanase isoforms in differential cell wall hydrolysis and fruit softening during ripening
    Lazan H, Ng SY, Goh LY, Ali ZM
    Plant Physiol Biochem, 2004 Dec;42(11):847-53.
    PMID: 15694277
    The potential significance of the previously reported papaya (Carica papaya L.) beta-galactosidase/galactanase (beta-d-galactoside galactohydrolase; EC 3.2.1.23) isoforms, beta-gal I, II and III, as softening enzymes during ripening was evaluated for hydrolysis of pectins while still structurally attached to unripe fruit cell wall, and hemicelluloses that were already solubilized in 4 M alkali. The enzymes were capable of differentially hydrolyzing the cell wall as evidenced by increased pectin solubility, pectin depolymerization, and degradation of the alkali-soluble hemicelluloses (ASH). This enzyme catalyzed in vitro changes to the cell walls reflecting in part the changes that occur in situ during ripening. beta-Galactosidase II was most effective in hydrolyzing pectin, followed by beta-gal III and I. The reverse appeared to be true with respect to the hemicelluloses. Hemicellulose, which was already released from any architectural constraints, seemed to be hydrolyzed more extensively than the pectins. The ability of the beta-galactanases to markedly hydrolyze pectin and hemicellulose suggests that galactans provide a structural cross-linkage between the cell wall components. Collectively, the results support the case for a functional relevance of the papaya enzymes in softening related changes during ripening.
    Matched MeSH terms: Glycoside Hydrolases/metabolism*
  20. Fulltext An Overview into Polyethylene Terephthalate (PET) Hydrolases and Efforts in Tailoring Enzymes for Improved Plastic Degradation
    Khairul Anuar NFS, Huyop F, Ur-Rehman G, Abdullah F, Normi YM, Sabullah MK, et al.
    Int J Mol Sci, 2022 Oct 20;23(20).
    PMID: 36293501 DOI: 10.3390/ijms232012644
    Plastic or microplastic pollution is a global threat affecting ecosystems, with the current generation reaching as much as 400 metric tons per/year. Soil ecosystems comprising agricultural lands act as microplastics sinks, though the impact could be unexpectedly more far-reaching. This is troubling as most plastic forms, such as polyethylene terephthalate (PET), formed from polymerized terephthalic acid (TPA) and ethylene glycol (EG) monomers, are non-biodegradable environmental pollutants. The current approach to use mechanical, thermal, and chemical-based treatments to reduce PET waste remains cost-prohibitive and could potentially produce toxic secondary pollutants. Thus, better remediation methods must be developed to deal with plastic pollutants in marine and terrestrial environments. Enzymatic treatments could be a plausible avenue to overcome plastic pollutants, given the near-ambient conditions under which enzymes function without the need for chemicals. The discovery of several PET hydrolases, along with further modification of the enzymes, has considerably aided efforts to improve their ability to degrade the ester bond of PET. Hence, this review emphasizes PET-degrading microbial hydrolases and their contribution to alleviating environmental microplastics. Information on the molecular and degradation mechanisms of PET is also highlighted in this review, which might be useful in the future rational engineering of PET-hydrolyzing enzymes.
    Matched MeSH terms: Hydrolases/metabolism
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