Interactions of β-Lactoglobulin with Bovine Submaxillary Mucin vs. Porcine Gastric Mucin: The Role of Hydrophobic and Hydrophilic Residues as Studied by Fluorescence Spectroscopy

The aim of this study was to investigate binding interactions between β-lactoglobulin (BLG) and two different mucins, bovine submaxillary mucins (BSM) and porcine gastric mucin (PGM), using intrinsic and extrinsic fluorescence spectroscopies. Intrinsic fluorescence spectra showed an enhanced decrease of fluorescence intensity of BLG at all pH conditions when BLG was mixed with PGM rather than with BSM. We propose that, unlike BSM, the tertiary structure of PGM changes and the hydrophobic regions are exposed at pH 3 due to protonation of negatively charged residues. Results suggest that PGM also facilitated the structural unfolding of BLG and its binding with PGM by a hydrophobic interaction, especially at acidic pH, which was further supported by extrinsic fluorescence spectroscopy. Hydrophobic interaction is suggested as the dominant interaction mechanism between BLG and PGM at pH 3, whereas electrostatic interaction is the dominant one between BLG and BSM.

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Binding of CML-Modified as Well as Heat-Glycated β-lactoglobulin to Receptors for AGEs Is Determined by Charge and Hydrophobicity

International Journal of Molecular Sciences ◽

10.3390/ijms21124567 ◽

2020 ◽

Vol 21 (12) ◽

pp. 4567 ◽

Cited By ~ 1

Author(s):

Hannah E. Zenker ◽

Malgorzata Teodorowicz ◽

Arifa Ewaz ◽

R.J. Joost van Neerven ◽

Huub F.J. Savelkoul ◽

...

Keyword(s):

Secondary Structure ◽

Tertiary Structure ◽

Glyoxylic Acid ◽

Native Page ◽

Galectin 3 ◽

Carboxymethyl Lysine ◽

Antigen Presenting ◽

Age Receptors ◽

Β Lactoglobulin

Intake of dietary advanced glycation end products (AGEs) is associated with inflammation-related health problems. Nε-carboxymethyl lysine (CML) is one of the best characterised AGEs in processed food. AGEs have been described as ligands for receptors present on antigen presenting cells. However, changes in protein secondary and tertiary structure also induce binding to AGE receptors. We aimed to discriminate the role of different protein modifications in binding to AGE receptors. Therefore, β-lactoglobulin was chemically modified with glyoxylic acid to produce CML and compared to β-lactoglobulin glycated with lactose. Secondary structure was monitored with circular dichroism, while hydrophobicity and formation of β-sheet structures was measured with ANS-assay and ThT-assay, respectively. Aggregation was monitored using native-PAGE. Binding to sRAGE, CD36, and galectin-3 was measured using inhibition ELISA. Even though no changes in secondary structure were observed in all tested samples, binding to AGE receptors increased with CML concentration of CML-modified β-lactoglobulin. The negative charge of CML was a crucial determinant for the binding of protein bound CML, while binding of glycated BLG was determined by increasing hydrophobicity. This shows that sRAGE, galectin-3, and CD36 bind to protein bound CML and points out the role of negatively charged AGEs in binding to AGE receptors.

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Modulation of Macrophages M1/M2 Polarization Using Carbohydrate-Functionalized Polymeric Nanoparticles

Polymers ◽

10.3390/polym13010088 ◽

2020 ◽

Vol 13 (1) ◽

pp. 88

Author(s):

Raquel G. D. Andrade ◽

Bruno Reis ◽

Benjamin Costas ◽

Sofia A. Costa Lima ◽

Salette Reis

Keyword(s):

Inflammatory Responses ◽

Polymeric Nanoparticles ◽

Interaction Mechanism ◽

Mannose Receptor ◽

The Body ◽

Receptor Expression ◽

Production Methods ◽

Polymeric Nanocarriers ◽

Efficient Delivery

Exploiting surface endocytosis receptors using carbohydrate-conjugated nanocarriers brings outstanding approaches to an efficient delivery towards a specific target. Macrophages are cells of innate immunity found throughout the body. Plasticity of macrophages is evidenced by alterations in phenotypic polarization in response to stimuli, and is associated with changes in effector molecules, receptor expression, and cytokine profile. M1-polarized macrophages are involved in pro-inflammatory responses while M2 macrophages are capable of anti-inflammatory response and tissue repair. Modulation of macrophages’ activation state is an effective approach for several disease therapies, mediated by carbohydrate-coated nanocarriers. In this review, polymeric nanocarriers targeting macrophages are described in terms of production methods and conjugation strategies, highlighting the role of mannose receptor in the polarization of macrophages, and targeting approaches for infectious diseases, cancer immunotherapy, and prevention. Translation of this nanomedicine approach still requires further elucidation of the interaction mechanism between nanocarriers and macrophages towards clinical applications.

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Role of Autochthonous Filamentous Fungi in Bioremediation of a Soil Historically Contaminated with Aromatic Hydrocarbons

Applied and Environmental Microbiology ◽

10.1128/aem.72.1.28-36.2006 ◽

2006 ◽

Vol 72 (1) ◽

pp. 28-36 ◽

Cited By ~ 98

Author(s):

A. D'Annibale ◽

F. Rosetto ◽

V. Leonardi ◽

F. Federici ◽

M. Petruccioli

Keyword(s):

Aromatic Hydrocarbons ◽

Contaminated Soil ◽

Chloride Ions ◽

Lepidium Sativum ◽

Fungal Colonization ◽

Soil Toxicity ◽

Germination Test ◽

Lignin Peroxidases ◽

Ph Conditions

ABSTRACT Nine fungal strains isolated from an aged and heavily contaminated soil were identified and screened to assess their degradative potential. Among them, Allescheriella sp. strain DABAC 1, Stachybotrys sp. strain DABAC 3, and Phlebia sp. strain DABAC 9 were selected for remediation trials on the basis of Poly R-478 decolorization associated with lignin-modifying enzyme (LME) production. These autochthonous fungi were tested for the abilities to grow under nonsterile conditions and to degrade various aromatic hydrocarbons in the same contaminated soil. After 30 days, fungal colonization was clearly visible and was confirmed by ergosterol determination. In spite of subalkaline pH conditions and the presence of heavy metals, the autochthonous fungi produced laccase and Mn and lignin peroxidases. No LME activities were detected in control microcosms. All of the isolates led to a marked removal of naphthalene, dichloroaniline isomers, o-hydroxybiphenyl, and 1,1′-binaphthalene. Stachybotrys sp. strain DABAC 3 was the most effective isolate due to its ability to partially deplete the predominant contaminants 9,10-anthracenedione and 7H-benz[DE]anthracen-7-one. A release of chloride ions was observed in soil treated with either Allescheriella sp. strain DABAC 1 or Stachybotrys sp. strain DABAC 3, suggesting the occurrence of oxidative dehalogenation. The autochthonous fungi led to a significant decrease in soil toxicity, as assessed by both the Lepidium sativum L. germination test and the Collembola mortality test.

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SUMOylation Negatively Regulates Angiogenesis by Targeting Endothelial NOTCH Signaling

Circulation Research ◽

10.1161/circresaha.117.310696 ◽

2017 ◽

Vol 121 (6) ◽

pp. 636-649 ◽

Cited By ~ 15

Author(s):

Xiaolong Zhu ◽

Sha Ding ◽

Cong Qiu ◽

Yanna Shi ◽

Lin Song ◽

...

Keyword(s):

Notch Signaling ◽

Cell Fate ◽

Developmental Disorders ◽

Interaction Mechanism ◽

Growth Factor Receptor ◽

Vascular Diseases ◽

Cell Interaction ◽

Protein Signaling

Rationale: The highly conserved NOTCH (neurogenic locus notch homolog protein) signaling pathway functions as a key cell–cell interaction mechanism controlling cell fate and tissue patterning, whereas its dysregulation is implicated in a variety of developmental disorders and cancers. The pivotal role of endothelial NOTCH in regulation of angiogenesis is widely appreciated; however, little is known about what controls its signal transduction. Our previous study indicated the potential role of post-translational SUMO (small ubiquitin-like modifier) modification (SUMOylation) in vascular disorders. Objective: The aim of this study was to investigate the role of SUMOylation in endothelial NOTCH signaling and angiogenesis. Methods and Results: Endothelial SENP1 (sentrin-specific protease 1) deletion, in newly generated endothelial SENP1 (the major protease of the SUMO system)–deficient mice, significantly delayed retinal vascularization by maintaining prolonged NOTCH1 signaling, as confirmed in cultured endothelial cells. An in vitro SUMOylation assay and immunoprecipitation revealed that when SENP1 associated with N1ICD (NOTCH1 intracellular domain), it functions as a deSUMOylase of N1ICD SUMOylation on conserved lysines. Immunoblot and immunoprecipitation analyses and dual-luciferase assays of natural and SUMO-conjugated/nonconjugated NOTCH1 forms demonstrated that SUMO conjugation facilitated NOTCH1 cleavage. This released N1ICD from the membrane and stabilized it for translocation to the nucleus where it functions as a cotranscriptional factor. Functionally, SENP1-mediated NOTCH1 deSUMOylation was required for NOTCH signal activation in response to DLL4 (Delta-like 4) stimulation. This in turn suppressed VEGF (vascular endothelial growth factor) receptor signaling and angiogenesis, as evidenced by immunoblotted signaling molecules and in vitro angiogenesis assays. Conclusions: These results establish reversible NOTCH1 SUMOylation as a regulatory mechanism in coordinating endothelial angiogenic signaling; SENP1 acts as a critical intrinsic mediator of this process. These findings may apply to NOTCH-regulated biological events in nonvascular tissues and provide a novel therapeutic strategy for vascular diseases and tumors.

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An optimized purification process for porcine gastric mucin with preservation of its native functional properties

RSC Advances ◽

10.1039/c6ra07424c ◽

2016 ◽

Vol 6 (50) ◽

pp. 44932-44943 ◽

Cited By ~ 42

Author(s):

Veronika J. Schömig ◽

Benjamin T. Käsdorf ◽

Christoph Scholz ◽

Konstantinia Bidmon ◽

Oliver Lieleg ◽

...

Keyword(s):

Functional Properties ◽

Gastric Mucin ◽

Acidic Ph ◽

Gel Formation ◽

Purification Process ◽

Porcine Gastric Mucin

The purification of porcine gastric mucin was optimized and key properties such as gel formation at acidic pH, lubrication behavior and interactions of mucins with charged molecules were preserved.

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