On the role of alginate structure in complexing with lysozyme and application for enzyme delivery

Werner, J.; Nareddy, Pavan Kumar; Moreno‐Villoslada, Ignacio; Moerschbacher, Bruno M.; Swamy, Musti J.; Pan, Shu; Ostermeier, Marc; Goycoolea, Francisco M.

doi:10.1016/j.foodhyd.2015.04.017

Cited by 55 publications

(33 citation statements)

References 62 publications

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“…We found that the interaction was enthalpy driven, possibly reflecting the occurrence of multiple contact points at the binding site made possible by hydrogen bonds, van der Waals interactions, protonation, or ligand-induced conformational changes in the protein’s binding pocket 32 33 . Complementarily, the entropic cost may reflect the enzyme’s need to structurally fix the highly flexible ulvan molecule, which is achieved by locking the polysaccharide in a particular conformation and decreases its rotational and translational freedom 33 34 . The affinity between proteins and carbohydrates is typically rather low, usually in the millimolar range 32 .…”

Section: Discussionmentioning

confidence: 99%

Revised domain structure of ulvan lyase and characterization of the first ulvan binding domain

Melcher

Neumann

Werner

et al. 2017

Sci Rep

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Biomass waste products from green algae have recently been given new life, as these polysaccharides have potential applications in industry, agriculture, and medicine. One such polysaccharide group called ulvans displays many different, potentially useful properties that arise from their structural versatility. Hence, performing structural analyses on ulvan is crucial for future applications. However, chemical reaction–based analysis methods cannot fully characterize ulvan and tend to alter its structure. Thus, better methods require well-characterized ulvan-degrading enzymes. Therefore, we analysed a previously sequenced ulvan lyase (GenebankTM reference number JN104480) and characterized its domains. We suggest that the enzyme consists of a shorter than previously described catalytic domain, a newly identified substrate binding domain, and a C-terminal type 9 secretion system signal peptide. By separately expressing the two domains in E. coli, we confirmed that the binding domain is ulvan specific, having higher affinity for ulvan than most lectins for their ligands (affinity constant: 105 M−1). To our knowledge, this is the first description of an ulvan-binding domain. Overall, identifying this new binding domain is one step towards engineering ulvan enzymes that can be used to characterize ulvan, e.g. through enzymatic/mass spectrometric fingerprinting analyses, and help unlock its full potential.

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Section: Discussionmentioning

confidence: 99%

Revised domain structure of ulvan lyase and characterization of the first ulvan binding domain

Melcher

Neumann

Werner

et al. 2017

Sci Rep

Self Cite

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“…The different release times can be explained by the nature of the chemical interactions between the active agent and the polymers, the hydrophilicity of the nanoparticles, and closing of the polymeric network [42]. The pKa values of the mannuronic and guluronic acid residues in the ALG polymer are 3.38 and 3.65, respectively [43], while the values are 6.5 for CS [44] and 4 for GA 3 . The final pH of the nanoparticles (4.9) indicated that the GA 3 was deprotonated, enabling electrostatic interactions between the active agent and the surfaces of the CS/TPP nanoparticles (which presented a positive zeta potential).…”

Section: Release Kinetics Assaysmentioning

confidence: 99%

Chitosan nanoparticles as carrier systems for the plant growth hormone gibberellic acid

Pereira

Silva

Oliveira

et al. 2017

Colloids and Surfaces B: Biointerfaces

170

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This work concerns the development of nanocarriers composed of alginate/chitosan (ALG/CS) and chitosan/tripolyphosphate (CS/TPP) for the plant growth regulator gibberellic acid (GA). ALG/CS nanoparticles with and without GA presented mean size of 450±10nm, polydispersity index (PDI) of 0.3, zeta potential of -29±0.5mV, concentrations of 1.52×10 and 1.92×10 nanoparticles mL, respectively, and 100% encapsulation efficiency. CS/TPP nanoparticles with and without GA presented mean size of 195±1nm, PDI of 0.3, zeta potential of +27±3mV, concentrations of 1.92×10 and 3.54×10 nanoparticles mL, respectively, and 90% encapsulation efficiency. The nanoparticles were stable during 60days and the two systems differed in terms of the release mechanism, with the release depending on factors such as pH and temperature. Bioactivity assays using Phaseolus vulgaris showed that the ALG/CS-GA nanoparticles were most effective in increasing leaf area and the levels of chlorophylls and carotenoids. The systems developed showed good potential, providing greater stability and efficiency of this plant hormone in agricultural applications.

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“…Further, one can see that both the values for the binding enthalpies and T Δ S have a negative sign and that both processes tend to compensate each other, as displayed in Figure . Thus, the porphyrin association with G4 dendrimer reducing the particle number and possibly also the flexibility of the dendrimer enforces order and causes a decrease in entropy, a classical phenomenon observed in many types of self‐assembly . Figure indicates that the decrease of Δ H upon association becomes compensated by the entropy loss due to the binding of the polyelectrolyte to the porphyrin such that the relative magnitude of enthalpy and entropy does not vary, as also given in Table .…”

Section: Resultsmentioning

confidence: 79%

Metalloporphyrin–polyelectrolyte assemblies in aqueous solution: Influence of the metal center and the polyelectrolyte architecture

Frühbeißer

Werner

Gröhn

2017

J Polym Sci B Polym Phys

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This study investigates the influence of different metal centers in porphyrins and of different polyelectrolyte architectures on the formation of supramolecular metalloporphyrin-polyelectrolyte assemblies in aqueous solution via electrostatic self-assembly. Metal-analogues of the tetravalent anionic meso-tetrakis(4-sulfonatophenyl)-porphyrin (with Zn 21 , Co 21 , Ni 21 , Mn 31 , and Fe 31 ) are combined with the cationic dendrimer of generation 4 or with the linear polydiallyldimethylammoniumchloride. Dynamic light scattering and atomic force microscopy reveal that the different molecular geometries of the metalloporphyrins resulting from axial ligands determine the size and the stability of the aggregates. A thermodynamic study elucidates the importance of the polymer architecture in controlling the size of the assembly and the role of the metal center.

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On the role of alginate structure in complexing with lysozyme and application for enzyme delivery

Cited by 55 publications

References 62 publications

Revised domain structure of ulvan lyase and characterization of the first ulvan binding domain

Revised domain structure of ulvan lyase and characterization of the first ulvan binding domain

Chitosan nanoparticles as carrier systems for the plant growth hormone gibberellic acid

Metalloporphyrin–polyelectrolyte assemblies in aqueous solution: Influence of the metal center and the polyelectrolyte architecture

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