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Pires CL, Rodrigues SD, Bristot D, Hessel Gaeta H, de Oliveira Toyama D, Ronald Lobo Farias W, Hikari Toyama M. Sulfated polysaccharide extracted of the green algae Caulerpa racemosa increase the enzymatic activity and paw edema induced by sPLA2 from Crotalus durissus terrificus venom. REVISTA BRASILEIRA DE FARMACOGNOSIA 2013. [DOI: 10.1590/s0102-695x2013005000050] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Huang WN, Chen YH, Chen CL, Wu W. Surface pressure-dependent interactions of secretory phospholipase A2 with zwitterionic phospholipid membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:7034-7041. [PMID: 21557547 DOI: 10.1021/la200255r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The hydrolytic activity of secretory phospholipase A(2) (PLA(2)) is regulated by many factors, including the physical state of substrate aggregates and the chemical nature of phospholipid molecules. In order to achieve strong binding of PLA(2) on its substrates, many previous works have used anionic lipid dispersion to characterize the orientation and penetration depth of PLA(2) molecules on membrane surfaces. In this study, we applied monolayer technique with controllable surface area to investigate the PLA(2)s of Taiwan cobra venom and bee venom on zwitterionic phophatidylcholine monolayers and demonstrated an optimum hydrolytic activity at a surface pressure of 18 and 24 mN/m, respectively. By combining polarized attenuated total reflection Fourier-transform infrared spectroscopy and monolayer-binding experiments, we found that the amount of membrane-bound PLA(2) decreased markedly as the surface pressure of the monolayer was increased. Interestingly, the insertion area of the PLA(2)s decreased to near zero as the surface pressure increased to the optimum pressure for hydrolytic activity. On the basis of the measured infrared dichroic ratio, the orientation of the PLA(2)s bound to zwitterionic membranes was similar to that observed on a negatively charged membrane and was independent of the surface pressure. Our findings suggest that both PLA(2)s were located on the membrane surface rather than penetrating the membrane bilayer and that the deeply inserted mode is not a favorable condition for the hydrolysis of phospholipids in zwitterionic phospholipid membranes. The results are discussed in terms of the easy access of catalytic water for the PLA(2) activity and the mobilization of its substrate and product to facilitate the catalytic process.
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Affiliation(s)
- Wei-Ning Huang
- Department of Biotechnology, Yuanpei University, Hsinchu, Taiwan.
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A biophysical approach to phospholipase A2 activity and inhibition by anti-inflammatory drugs. Biophys Chem 2010; 152:109-17. [DOI: 10.1016/j.bpc.2010.08.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2010] [Revised: 08/14/2010] [Accepted: 08/17/2010] [Indexed: 11/18/2022]
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Genistein, a potent inhibitor of secretory phospholipase A2: a new insight in down regulation of inflammation. Inflammopharmacology 2009; 18:25-31. [DOI: 10.1007/s10787-009-0018-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2009] [Accepted: 10/14/2009] [Indexed: 12/29/2022]
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Chung K, Kim J, Cho BK, Ko BJ, Hwang BY, Kim BG. How does dextran sulfate prevent heat induced aggregation of protein?: The mechanism and its limitation as aggregation inhibitor. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2007; 1774:249-57. [PMID: 17223396 DOI: 10.1016/j.bbapap.2006.11.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2006] [Revised: 11/02/2006] [Accepted: 11/30/2006] [Indexed: 10/23/2022]
Abstract
The effect of dextran sulfate on protein aggregation was investigated to provide the clues of its biochemical mechanism. The interaction between dextran sulfate and BSA varied with the pH values of the solution, which led to the different extent of aggregation prevention by dextran sulfate. Light scattering data with thermal scan showed that dextran sulfate suppressed BSA aggregation at pH 5.1 and pH 6.2, while it had no effect at pH 7.5. Isothermal titration calorimetric analysis suggested that the pH dependency of the role of dextran sulfate on BSA aggregation would be related to the difference in the mode of BSA-dextran sulfate complex formation. Isothermal titration calorimetric analysis at pH 6.2 indicated that dextran sulfate did not bind to native BSA at this pH, but interacted with partially unfolded BSA. While stabilizing native form of protein by the complex formation has been suggested as the suitable mechanism of preventing aggregation, our observation of conformational changes by circular dichroism spectroscopy showed that strong electrostatic interaction between dextran sulfate and BSA rather facilitated the denaturation of BSA. Combining the data from isothermal titration calorimetry, circular dichroism, and dynamic light scattering, we found that the complex formation of the intermediate state of denatured BSA with dextran sulfate is a prerequisite to suppress the aggregation by preventing further oligomerization/aggregation process of denatured protein.
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Affiliation(s)
- Kwanghun Chung
- School of Chemical and Biological Engineering, Seoul National University, Seoul 151-742, Korea
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Jameel NM, Shekhar MA, Vishwanath BS. α-lipoic acid: An inhibitor of secretory phospholipase A2 with anti-inflammatory activity. Life Sci 2006; 80:146-53. [PMID: 17011589 DOI: 10.1016/j.lfs.2006.08.032] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2006] [Revised: 08/17/2006] [Accepted: 08/28/2006] [Indexed: 11/17/2022]
Abstract
Alpha-lipoic acid (ALA) and its reduced form dihydrolipoic acid (DHLA) are powerful antioxidants both in hydrophilic and lipophylic environments with diverse pharmacological properties including anti-inflammatory activity. The mechanism of anti-inflammatory activity of ALA and DHALA is not known. The present study describes the interaction of ALA and DHALA with pro-inflammatory secretory PLA(2) enzymes from inflammatory fluids and snake venoms. In vitro enzymatic inhibition of sPLA(2) from Vipera russellii, Naja naja and partially purified sPLA(2) enzymes from human ascitic fluid (HAF), human pleural fluid (HPF) and normal human serum (HS) by ALA and DHLA was studied using (14)C-oleate labeled Escherichia coli as the substrate. Biophysical interaction of ALA with sPLA(2) was studied by fluorescent spectral analysis and circular dichroism studies. In vivo anti-inflammatory activity was checked using sPLA(2) induced mouse paw edema model. ALA but not DHLA inhibited purified sPLA(2) enzymes from V. russellii, N. naja and partially purified HAF, HPF and HS in a dose dependent manner. This data indicated that ALA is critical for inhibition. IC(50) value calculated for these enzymes ranges from 0.75 to 3.0 microM. The inhibition is independent of calcium and substrate concentration. Inflammatory sPLA(2) enzymes are more sensitive to inhibition by ALA than snake venom sPLA(2) enzymes. ALA quenched the fluorescence intensity of sPLA(2) enzyme in a dose dependent manner. Apparent shift in the far UV-CD spectra of sPLA(2) with ALA indicated change in its alpha-helical confirmation and these results suggest its direct interaction with the enzyme. ALA inhibits the sPLA(2) induced mouse paw edema in a dose dependent manner and confirms the sPLA(2) inhibitory activity in vivo also. These data suggest that ALA may act as an endogenous regulator of sPLA(2) enzyme activity and suppress inflammatory reactions.
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Affiliation(s)
- Noor Mohamed Jameel
- Department of Studies in Biochemistry, University of Mysore, Manasagangothri, Mysore-570006, Karnataka, India
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Jameel NM, Frey BM, Frey FJ, Gowda TV, Vishwanath BS. Inhibition of secretory phospholipase A(2) enzyme by bilirubin: a new role as endogenous anti-inflammatory molecule. Mol Cell Biochem 2006; 276:219-25. [PMID: 16132704 DOI: 10.1007/s11010-005-4441-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2005] [Accepted: 03/23/2005] [Indexed: 10/25/2022]
Abstract
Bilirubin is a powerful antioxidant that suppresses the inflammatory process. However its interaction with proinflammatory PLA(2) enzyme is not known. Inhibition of several secretory phospholipase A(2) (sPLA(2)) enzyme activities by bilirubin was studied using (14)C-oleate labeled Escherichia coli as substrate. Bilirubin inhibits purified sPLA(2) enzyme from Vipera russellii and Naja naja venom and partially purified sPLA(2) enzymes from human ascitic fluid, pleural fluid and normal serum in a dose dependent manner. IC(50) values calculated for these enzymes ranges from 1.75 to 10.5 microM. Inflammatory human sPLA(2) enzymes are more sensitive to inhibition by bilirubin than snake venom sPLA(2)s. Inhibition of sPLA(2) activity by bilirubin is independent of calcium concentration. Increasing substrate concentration (upto 180 nmol) did not relieve the inhibition of sPLA(2) by bilirubin and it is irreversible. Bilirubin quenched the relative fluorescence intensity of sPLA(2) in a dose dependent manner in the same concentration range at which in vitro sPLA(2) inhibition was observed. In the presence of bilirubin, apparent shift in the far UV-CD spectra of sPLA(2) was observed, indicating a direct interaction with the enzyme. Inhibition of sPLA(2) induced mouse paw edema by bilirubin confirms its sPLA(2) inhibitory activity in vivo also. These findings indicate that inhibition of sPLA(2) by bilirubin is mediated by direct interaction with the enzyme and bilirubin may act as an endogenous regulator of sPLA(2) enzyme activity.
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Affiliation(s)
- Noor Mohamed Jameel
- Department of Studies in Biochemistry, University of Mysore, Manasagangothri, Mysore 570 006, India.
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Bugs MR, Bortoleto-Bugs RK, Cornélio ML. The interaction between heparin and Lys49 phospholipase A2 reveals the natural binding of heparin on the enzyme. Int J Biol Macromol 2005; 37:21-7. [PMID: 16197992 DOI: 10.1016/j.ijbiomac.2005.08.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2005] [Revised: 08/01/2005] [Accepted: 08/04/2005] [Indexed: 11/21/2022]
Abstract
We have studied at a molecular level the interaction of heparins on bothropstoxin-I (BthTx-I), a phospholipase A2 toxin. The protein was monitored using gel filtration chromatography, dynamic light scattering (DLS), circular dichroism (CD), attenuated total reflectance Fourier transform infrared (ATR-FTIR) and intrinsic tryptophan fluorescence emission (ITFE) spectroscopy. The elution profile of the protein presents a displacement of the protein peak to larger complexes when interacting with higher concentration of heparin. The DLS results shows two Rh at a molar ratio of 1, one to the distribution of the protein and the second for the action of heparin on BthTx-I structures, and a large distribution with the increase of protein. The interaction is accompanied by significant changes in the CD spectra, showing two common features: a decrease in signal at 208 nm (3 and 6 kDa heparins) and an isodichroic point near 226 nm (3 kDa heparin). FTIR spectra indicate that only a few amino acid residues are involved in this interaction. Alterations in the ITFE by binding heparins suggest that the initial binding occurs on the ventral face of BthTx-I. Together, these results add an experimental and structural basis on the action mechanism of the heparins over the phospholipases A2 and provide a molecular model to elucidate the interaction of the enzyme-heparin complex at a molecular level.
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Affiliation(s)
- Milton Roque Bugs
- Department of Physics, IBILCE/UNESP, Rua Cristóvão Colombo, 2265, CEP 15054-000 São José do Rio Preto, SP, Brazil.
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Forouhar F, Huang WN, Liu JH, Chien KY, Wu WG, Hsiao CD. Structural basis of membrane-induced cardiotoxin A3 oligomerization. J Biol Chem 2003; 278:21980-8. [PMID: 12660250 DOI: 10.1074/jbc.m208650200] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cobra cardiotoxins (CTXs) have previously been shown to induce membrane fusion of vesicles formed by phospholipids such as cardiolipin or sphingomyelin. CTX can also form a pore in membrane bilayers containing a anionic lipid such as phosphatidylserine or phosphatidylglycerol. Herein, we show that the interaction of CTX with negatively charged lipids causes CTX dimerization, an important intermediate for the eventual oligomerization of CTX during the CTX-induced fusion and pore formation process. The structural basis of the lipid-induced oligomerization of CTX A3, a major CTX from Naja atra, is then illustrated by the crystal structure of CTX A3 in complex with SDS; SDS likely mimics anionic lipids of the membrane under micelle conditions at 1.9-A resolution. The crystal packing reveals distinct SDS-free and SDS-rich regions; in the latter two types of interconnecting CTX A3 dimers, D1 and D2, and several SDS molecules can be identified to stabilize D1 and D2 by simultaneously interacting with residues at each dimer interface. When the three CTXSDS complexes in the asymmetric unit are overlaid, the orientation of CTX A3 monomers relative to the SDS molecules in the crystal is strikingly similar to that of the toxin with respect to model membranes as determined by NMR and Fourier transform infrared methods. These results not only illustrate how lipid-induced CTX dimer formation may be transformed into oligomers either as inverted micelles of fusion intermediates or as membrane pore of anionic lipid bilayers but also underscore a potential role for SDS in x-ray diffraction study of protein-membrane interactions in the future.
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Affiliation(s)
- Farhad Forouhar
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan 115
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Wu CW, Cheng SF, Huang WN, Trivedi VD, Veeramuthu B, Assen B K, Wu WG, Chang DK. Effects of alterations of the amino-terminal glycine of influenza hemagglutinin fusion peptide on its structure, organization and membrane interactions. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1612:41-51. [PMID: 12729928 DOI: 10.1016/s0005-2736(03)00084-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mutations of the glycine residue at the amino terminus of HA2 have been shown to have a large effect on the fusion activity of HA2, the extent of which apparently correlates with the side chain bulkiness of the substituting amino acids. To investigate into the cause of abrogation in fusogenicity and virus-promoted fusion mechanism, we synthesized several peptides in which this glycine was substituted by serine, glutamic acid, or lysine. 1,2-Dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dimyristoyl sn-glycero-3-phosphoglycerol (DMPG) were used as model membranes in the fluorescence, circular dichroism (CD), and FTIR measurements while sodium dodecyl sulfate was used in NMR studies. We found that, for the less active variants, affinity to membrane, degree of solvent dehydration, lipid perturbation, depth of insertion, and helicity were less. Comparison of affinity to membrane bilayer among these analogs revealed that binding of the fusion peptide is determined largely by the hydrophobic effect. Additionally, the orientation is closer to the membrane normal for the wild-type fusion peptide in the helix form while the inactive analogs inserted more parallel to the membrane surface.
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Affiliation(s)
- Cheng-Wei Wu
- Institute of Chemistry, Academia Sinica, 115, Taipei, Taiwan, ROC
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Sue SC, Chien KY, Huang WN, Abraham JK, Chen KM, Wu WG. Heparin binding stabilizes the membrane-bound form of cobra cardiotoxin. J Biol Chem 2002; 277:2666-73. [PMID: 11714697 DOI: 10.1074/jbc.m104887200] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
It has been shown previously that the long chain fragments of heparin bind to the beta-strand cationic belt of the three-finger cobra cardiotoxin (or cytotoxin, CTX) and hence enhance its penetration into phospholipid monolayer under physiological ionic conditions. By taking lysophosphatidylcholine (LPC) micelles as a membrane model, we have shown by (1)H NMR study that the binding of heparin-derived hexasaccharide (Hep-6) to CTX at the beta-strand region can induce conformational changes of CTX near its membrane binding loops and promote the binding activity of CTX toward LPC. The Fourier-transform infrared spectra and NMR nuclear Overhauser effect of Hep-6.CTX and CTX.LPC complex in aqueous buffer also supplemented the aforementioned observation. Thus, the detected conformational change may presumably be the result of structural coupling between the connecting loops and its beta-strands. This is the first documentation of results showing how the association of hydrophilic carbohydrate molecules with amphiphilic proteins can promote hydrophobic protein-lipid interaction via the stabilization of its membrane-bound form. A similar mechanism involving tripartite interactions of heparin, protein, and lipid molecules may be operative near the extracellular matrix of cell membranes.
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Affiliation(s)
- Shih-Che Sue
- Department of Life Sciences, National Tsing Hua University, Hsinchu 30043, Taiwan
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