Binding of alkaloids into the S1 specificity pocket of α-chymotrypsin: Evidence from induced circular dichroism spectra

Zsila, Ferenc; Kámán, Judit; Bogányi, Borbála; Józsvai, Dávid

doi:10.1039/c0ob01221a

Cited by 16 publications

(15 citation statements)

References 51 publications

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“…Merkel et al (2012), using a similar in vitro digestion model, also found degradation (at a moderate extent) of some ergot alkaloids by digestive juices, which was simply attributed to the presence of the digestive enzymes and varying pH conditions. On the other hand, it has been recently shown that some plant alkaloids can bind to bovine a-chymotrypsin (Zsila, K am an, Bog anyi, & J ozsvai, 2011) and fungal a-amylase (Tintu, Dileep, Augustine, & Sadasivan, 2012). Therefore, the possibility of the decreasing in CYN concentration measured during this experiment being due to the binding of CYN to digestive enzymes and its subsequent nondetection, cannot be discarded.…”

Section: Bioaccessibility Of Cynmentioning

confidence: 88%

Bioaccessibility and changes on cylindrospermopsin concentration in edible mussels with storage and processing time

et al. 2016

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a b s t r a c tThe alkaloid cylindrospermopsin has been recognized of increased concern due to the global expansion of its main producer, Cylindrospermopsis raciborskii. Previous studies have shown that bivalves can accumulate high levels of cylindrospermopsin. Based on the potential for human health risks, a provisional tolerable daily intake of 0.03 mg/kg-body weight has been recommended. However, the human exposure assessment has been based on the cylindrospermopsin concentration in raw food items. Thus, this study aimed to assess the changes on cylindrospermopsin concentration in edible mussels with storage and processing time as well as cylindrospermopsin bioaccessibility. Mussels, (Mytilus galloprovincialis) fed cylindrospermopsin-producing C. raciborskii, were subjected to the treatments and then analyzed by LC-MS/MS. Mussels stored frozen allowed a significantly higher recovery of cylindrospermopsin (52.5% in 48 h and 57.7% in one week). The cooking treatments did not produce significant differences in cylindrospermopsin concentration in the mussel matrices (flesh), however, cylindrospermopsin was found in the cooking water, suggesting that heat processing can be used to reduce the availability of cylindrospermopsin. The in vitro digestion considerably decreased the cylindrospermopsin availability in uncooked and steamed mussels, highlighting the importance in integrating the bioaccessibility of cylindrospermopsinin in the human health risk assessment.

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Section: Bioaccessibility Of Cynmentioning

confidence: 88%

Bioaccessibility and changes on cylindrospermopsin concentration in edible mussels with storage and processing time

et al. 2016

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“…It coincides with the UV band centered at the same wavelength which represents the light absorption of the monomeric PQS species ( Figure 4 ). Accordingly, a monomeric fraction of PQS is also involved in the peptide binding and thus gives contribution to the induced CD activity presumably via the non-degenerate exciton coupling mechanism ( Zsila et al, 2011 ).…”

Section: Resultsmentioning

confidence: 99%

Quorum Sensing Pseudomonas Quinolone Signal Forms Chiral Supramolecular Assemblies With the Host Defense Peptide LL-37

Zsila

Ricci

Szigyártó

et al. 2021

Front. Mol. Biosci.

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Host defense antimicrobial peptides (HDPs) constitute an integral component of the innate immune system having nonspecific activity against a broad spectrum of microorganisms. They also have diverse biological functions in wound healing, angiogenesis, and immunomodulation, where it has also been demonstrated that they have a high affinity to interact with human lipid signaling molecules. Within bacterial biofilms, quorum sensing (QS), the vital bacterial cell-to-cell communication system, is maintained by similar diffusible small molecules which control phenotypic traits, virulence factors, biofilm formation, and dispersion. Efficient eradication of bacterial biofilms is of particular importance as these colonies greatly help individual cells to tolerate antibiotics and develop antimicrobial resistance. Regarding the antibacterial function, for several HDPs, including the human cathelicidin LL-37, affinity to eradicate biofilms can exceed their activity to kill individual bacteria. However, related underlying molecular mechanisms have not been explored yet. Here, we employed circular dichroism (CD) and UV/VIS spectroscopic analysis, which revealed that LL-37 exhibits QS signal affinity. This archetypal representative of HDPs interacts with the Pseudomonas quinolone signal (PQS) molecules, producing co-assemblies with peculiar optical activity. The binding of PQS onto the asymmetric peptide chains results in chiral supramolecular architectures consisting of helically disposed, J-aggregated molecules. Besides the well-known bacterial membrane disruption activity, our data propose a novel action mechanism of LL-37. As a specific case of the so-called quorum quenching, QS signal molecules captured by the peptide are sequestered inside co-assemblies, which may interfere with the microbial QS network helping to prevent and eradicate bacterial infections.

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“…Acridine derivatives are planar aromatic hydrocarbons, which include diaminoacridines such as proflavine (Figure a), which is known to intercalate between the DNA base pairs. Moreover, certain acridine derivatives, in particular proflavine, are known germicides against Gram‐positive bacteria, which may also result in DNA mutagenesis . The binding mode of proflavine to DNA has been investigated using a variety of methods, including fluorescence spectrometry, and theoretical calculations such as the van der Waals density for correlation energy, flow injection analysis, and NMR spectroscopy .…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, certain acridine derivatives, in particular proflavine, are known germicides against Gram-positive bacteria, which may also result in DNA mutagenesis. [12][13][14][15] The binding mode of proflavine to DNA has been investigated using a variety of methods, including fluorescence spectrometry, [16] and theoretical calculations such as the van der Waals density for correlation energy, [17][18][19] flow injection analysis, [20] and NMR spectroscopy. [21] The binding mode of the resulting [proflavine]/[DNA base] complex is dependent on the R-ratio.…”

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confidence: 99%

Binding mode of proflavine to DNA probed by polarized light spectroscopy

Jin

Sung

Jang

2018

J Chinese Chemical Soc

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It is well known that proflavine binds to DNA. Here we investigate the binding mode of proflavine to native DNA using absorption, circular dichroism (CD), and linear dichroism (LD) spectroscopy as well as by fluorescence techniques. The observed changes of proflavine upon complexation with DNA can be summarized as a red shift and hypochromism in the absorption spectrum. The negative LDr in the proflavine absorption region has a magnitude comparable to or larger than that of the DNA absorption region, confirming the intercalative binding mode of proflavine to DNA. Saturation of the LD spectrum in the proflavine absorption region at R = 0.25 and a decrease in the fluorescence intensity provide further evidence of intercalation. Furthermore, the coupling of electric transition of intercalated proflavine is observed. Although proflavine has been reported to position itself along the DNA stem at high [proflavine]/[DNA base] ratios, the spectral characteristics, which include a clear isosbestic point in the absorption spectrum and proportionality in the LD magnitude in the proflavine absorption region, do not show any possibility of exterior binding.

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Binding of alkaloids into the S1 specificity pocket of α-chymotrypsin: Evidence from induced circular dichroism spectra

Cited by 16 publications

References 51 publications

Bioaccessibility and changes on cylindrospermopsin concentration in edible mussels with storage and processing time

Bioaccessibility and changes on cylindrospermopsin concentration in edible mussels with storage and processing time

Quorum Sensing Pseudomonas Quinolone Signal Forms Chiral Supramolecular Assemblies With the Host Defense Peptide LL-37

Binding mode of proflavine to DNA probed by polarized light spectroscopy

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