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1.
Int J Mol Sci ; 21(6)2020 Mar 18.
Article in English | MEDLINE | ID: mdl-32197439

ABSTRACT

The processes of memory formation and its storage are extremely dynamic. Therefore, the determination of the nature and temporal evolution of the changes that underlie the molecular mechanisms of retrieval and cause reconsolidation of memory is the key to understanding memory formation. Retrieval induces the plasticity, which may result in reconsolidation of the original memory and needs critical molecular events to stabilize the memory or its extinction. 4-Chloro-DL-phenylalanine (P-chlorophenylalanine-PCPA) depresses the most limiting enzyme of serotonin synthesis the tryptophan hydroxylase. It is known that PCPA reduces the serotonin content in the brain up to 10 times in rats (see Methods). We hypothesized that the PCPA could behave the similar way in snails and could reduce the content of serotonin in snails. Therefore, we investigated the effect of PCPA injection on contextual memory reconsolidation using a protein synthesis blocker in snails after training according to two protocols of different intensities. The results obtained in training according to the first protocol using five electrical stimuli per day for 5 days showed that reminding the training environment against the background of injection of PCPA led to a significant decrease in contextual memory. At the same time, the results obtained in training according to the second protocol using three electrical stimuli per day for 5 days showed that reminding the training environment against the injection of PCPA did not result in a significant change in contextual memory. The obtain results allowed us to conclude that the mechanisms of processes developed during the reconsolidation of contextual memory after a reminding depend both on the intensity of learning and on the state of the serotonergic system.


Subject(s)
Behavior, Animal/drug effects , Fenclonine/pharmacology , Helix, Snails/metabolism , Memory/drug effects , Tryptophan Hydroxylase/antagonists & inhibitors , Animals , Tryptophan Hydroxylase/metabolism
2.
Biochemistry ; 58(45): 4570-4581, 2019 11 12.
Article in English | MEDLINE | ID: mdl-31633358

ABSTRACT

Metallothioneins (MTs) are cysteine-rich polypeptides that are naturally found coordinated to monovalent and/or divalent transition metal ions. Three metallothionein isoforms from the Roman snail Helix pomatia are known. They differ in their physiological metal load and in their specificity for transition metal ions such as Cd2+ (HpCdMT isoform) and Cu+ (HpCuMT isoform) or in the absence of a defined metal specificity (HpCd/CuMT isoform). We have determined the solution structure of the Cd-specific isoform (HpCdMT) by nuclear magnetic resonance spectroscopy using recombinant isotopically labeled protein loaded with Zn2+ or Cd2+. Both structures display two-domain architectures, where each domain comprises a characteristic three-metal cluster similar to that observed in the ß-domains of vertebrate MTs. The polypeptide backbone is well-structured over the entire sequence, including the interdomain linker. Interestingly, the two domains display mutual contacts, as observed before for the metallothionein of the snail Littorina littorea, to which both N- and C-terminal domains are highly similar. Increasing the length of the linker motionally decouples both domains and removes mutual contacts between them without having a strong effect on the stability of the individual domains. The structures of Cd6- and Zn6-HpCdMT are nearly identical. However, 15N relaxation, in particular 15N R2 rates, is accelerated for many residues of Zn6-HpCdMT but not for Cd6-HpCdMT, revealing the presence of conformational exchange effects. We suggest that this snail MT isoform is evolutionarily optimized for binding Cd rather than Zn.


Subject(s)
Cadmium/metabolism , Helix, Snails/metabolism , Metallothionein/metabolism , Zinc/metabolism , Animals , Binding Sites , Helix, Snails/chemistry , Metallothionein/chemistry , Models, Molecular , Nuclear Magnetic Resonance, Biomolecular , Protein Binding , Protein Conformation
3.
Bioorg Med Chem ; 27(6): 955-962, 2019 03 15.
Article in English | MEDLINE | ID: mdl-30738652

ABSTRACT

Sulfatases hydrolyze sulfated metabolites to their corresponding alcohols and are present in all domains of life. These enzymes have found major application in metabolic investigation of drugs, doping control analysis and recently in metabolomics. Interest in sulfatases has increased due to a link between metabolic processes involving sulfated metabolites and pathophysiological conditions in humans. Herein, we present the first comprehensive substrate specificity and kinetic analysis of the most commonly used arylsulfatase extracted from the snail Helix pomatia. In the past, this enzyme has been used in the form of a crude mixture of enzymes, however, recently we have purified this sulfatase for a new application in metabolomics-driven discovery of sulfated metabolites. To evaluate the substrate specificity of this promiscuous sulfatase, we have synthesized a series of new sulfated metabolites of diverse structure and employed a mass spectrometric assay for kinetic substrate hydrolysis evaluation. Our analysis of the purified enzyme revealed that the sulfatase has a strong preference for metabolites with a bi- or tricyclic aromatic scaffold and to a lesser extent for monocyclic aromatic phenols. This metabolite library and mass spectrometric method can be applied for the characterization of other sulfatases from humans and gut microbiota to investigate their involvement in disease development.


Subject(s)
Arylsulfatases/metabolism , Helix, Snails/enzymology , Animals , Helix, Snails/metabolism , Hydrolysis , Kinetics , Mass Spectrometry , Substrate Specificity
4.
Org Biomol Chem ; 16(46): 8899-8903, 2018 11 28.
Article in English | MEDLINE | ID: mdl-30264842

ABSTRACT

The study of complex multivalent carbohydrate-protein interactions remains highly complicated and sometimes rendered impossible due to aggregation problems. In this study, we demonstrate that bio-layer interferometry is an excellent complementary method to standard techniques such as SPR and ITC. Using tetra- and hexadecavalent GalNAc glycoconjugates and Helix pomatia agglutinin (HPA) as a model lectin, we were able to measure reliable kinetic and thermodynamic parameters of multivalent interactions going from the micro to the nanomolar range.


Subject(s)
Acetylgalactosamine/metabolism , Glycoconjugates/metabolism , Helix, Snails/metabolism , Interferometry/methods , Lectins/metabolism , Animals , Kinetics , Thermodynamics
5.
Ecotoxicol Environ Saf ; 148: 713-720, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29174990

ABSTRACT

The work is a continuation of two previous studies in which biomarker fatty acids (12 of 56 FA pools) were analysed in Helix pomatia L. after heterogeneous micro-supplementation of Zn and Cu (administered in five micro-doses in the form of salts and EDTA and lysine chelates). This time, peroxidation (PI) and unsaturation coefficients (UI) as biomarker were analysed. These indices were calculated based on the FA profile in the foot and hepatopancreas of snails. The correlation of frequently used oxidation status indicators of organisms (catalase - CAT, glutathione peroxidase - GPx, selenium-dependent peroxidase - se-GPx, superoxide dismutase - SOD, glutathione transferase - GST, glutathione reductase - GR, glutathione - GSH, carbonyl protein - CP, thiobarbituric acid reactive substances - TBARS) with the rarely used UI and PI ratios was analysed. It was found that the 12-week micro-exposure to Zn and Cu did not inhibit but rather stimulated antioxidative defence at a sufficient level to increase the values of peroxidation/unsaturation indices in comparison to the control groups. Induction of an opposite process to oxidation of fatty acids was demonstrated. Maximum activities and amounts of antioxidants as well as minima of protein and lipid decomposition were recorded in groups supplemented with 0.75mg/l Zn and 1.0mg/l Cu. The possibility of a direct use of fatty acids as well as peroxidation/unsaturation indices as sensitive and reproducible biomarkers of exposure and oxidative physiological status in snails was confirmed.


Subject(s)
Antioxidants/metabolism , Copper/pharmacology , Fatty Acids, Unsaturated/metabolism , Helix, Snails/drug effects , Lipid Peroxidation/drug effects , Lipid Peroxides/metabolism , Zinc/pharmacology , Animals , Biomarkers/metabolism , Copper/metabolism , Helix, Snails/metabolism , Hepatopancreas/metabolism , Oxidation-Reduction , Zinc/metabolism
6.
Ecotoxicol Environ Saf ; 148: 377-383, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29096264

ABSTRACT

The uptake of Cd and some biomarkers of exposure and effects have been investigated in specimens of land snail Cornu aspersum exposed to vaporized CdCl2 (10mg/L) for 7 days. The Cd levels quantified in snail's whole bodies confirmed Cd bioavailability trough vaporization and an higher accumulation in the midgut gland compared to the foot. Biological responses investigated showed a reduction of destabilization time of lysosomal membranes (NRRT) in hemocytes and an induction of catalase activities (CAT) in midgut gland. A further evidence of CdCl2 vaporized exposure was given by an increase in MT protein content as well as induction of Cd-MT gene expression, highlighting the central role of the midgut gland in Cd detoxification. These biomarkers can thus be considered as sensitive tools for the assessment of Cd contamination in the air using land snails as bioindicators. No changes in of GST activity and MDA were observed. From the overall results, the land snail, C. aspersum, could be used as good bioindicator of air quality for pollution monitoring purposes having shown clear signs of exposure and effects due Cd exposure by air.


Subject(s)
Air Pollutants/toxicity , Cadmium Chloride/toxicity , Helix, Snails/drug effects , Air Pollutants/pharmacokinetics , Animals , Biomarkers/metabolism , Cadmium/metabolism , Cadmium Chloride/pharmacokinetics , Digestive System/enzymology , Digestive System/metabolism , Environmental Monitoring , Helix, Snails/enzymology , Helix, Snails/metabolism , Hemocytes/metabolism , Volatilization
7.
Ecotoxicol Environ Saf ; 138: 223-230, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28068579

ABSTRACT

We analyzed the changes in the profile of fatty acids (FA) in the foot tissues and hepatopancreas (HP) of snails Helix pomatia exposed to five microdoses of zinc (0.1, 0.25, 0.5, 0.75, or 1mg/l) administered in the form of a pure salt solution and in the form of EDTA and lysine chelates. Selection from a pool of 56 fatty acids analyzed in snail tissues yielded a set of 12 biomarker acids undergoing significant changes in contact with toxic substances. The selection criteria included the greatest percentage among the FA profile and their significant role in physiological processes. The proposed palette of acids of the biomarker FAs comprised C16:0; C18:0; C23:0; C18:1 n-9; C20:1 n-9; C18:2 n-6; C18:3 n-3; C20:2; C20:4 n-6; C20:5 n-3; C22:4 n-6; and C22:5 n-3, and saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs), determined separately in the foot tissues and hepatopancreas. The significant (p=0.01) influence of the dose as well as the source of the zinc on its' concentration in the tissues and on changes in the fatty acid profiles. Among the three zinc forms administered to the snails, the highest bioaccumulation of zinc in both tissues was noted in the group receiving the Zn-EDTA chelate. The content of PUFAs increased as the supplementation with zinc increased up to 0.75mg/l, but at 1mg/l, the share of these FAs began to decrease. This trend was observed in both analyzed tissue types - foot and hepatopancreas. The dose of 1mg Zn/l might be considered as a threshold dose above which the saturation of FAs increases. The results proved that determination of FA profile in snails can be used in ecotoxicological research as a reliable test of the effect of trace doses of stressors. The micro-supplementation of the mollusks diet with zinc is an example of a non-routine approach to issues connected with both diet and toxicology.


Subject(s)
Chelating Agents/pharmacology , Fatty Acids, Monounsaturated/metabolism , Helix, Snails/metabolism , Hepatopancreas/metabolism , Lipid Metabolism/drug effects , Zinc/pharmacology , Animals , Biomarkers/metabolism , Chelating Agents/metabolism , Zinc/metabolism
8.
Bull Environ Contam Toxicol ; 96(4): 484-9, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26868644

ABSTRACT

The purpose of this study was to determine whether cadmium (Cd) accumulation and toxicity in the midgut gland of Helix pomatia snails living in a Cd-contaminated area were related to soil pH. Toxic responses in the midgut gland (i.e., increased vacuolization and lipid peroxidation) occurred in H. pomatia snails exhibiting the highest Cd levels in the gland (265-274 µg/g dry wt) and living on acidic soil (pH 5.3-5.5), while no toxicity was observed in snails accumulating less Cd (90 µg/g) and ranging on neutral soil (pH 7.0), despite the fact that total soil Cd was similar in the two cases. The accumulation of Cd in the gland was directly related to the water extractable Cd in soil, which in turn correlated inversely with soil pH, indicating that this factor had a significant effect on tissue Cd. It appeared further that the occurrence of Cd toxicity was associated with low levels of metallothionein in the gland of snails ranging on acidic soil.


Subject(s)
Cadmium/analysis , Digestive System/pathology , Helix, Snails/metabolism , Soil Pollutants/analysis , Soil/chemistry , Zinc/analysis , Animals , Cadmium/metabolism , Cadmium/toxicity , Digestive System/chemistry , Digestive System/drug effects , Environmental Monitoring , Helix, Snails/chemistry , Helix, Snails/drug effects , Hydrogen-Ion Concentration , Lipid Peroxidation/drug effects , Metallothionein/metabolism , Metallurgy , Poland , Soil Pollutants/metabolism , Soil Pollutants/toxicity , Zinc/metabolism
9.
Acta Biol Hung ; 67(4): 345-363, 2016 Dec.
Article in English | MEDLINE | ID: mdl-28000513

ABSTRACT

Earlier experiments demonstrated that in order to place protracted tentacles and thereby olfactory receptors in an appropriate position for optimal perception of odor stimuli extraordinary complex movements are required. Until recently both large scale tentacle movements and patterned tentacle movements have been attributed to the concerted involvement of the tentacle retractor muscle and muscles of tegumentum. Recently the existence of three novel muscles in the posterior tentacles of Helix has been discovered. The present review, based on experimental data obtained by our research group, outlines the anatomy, physiology and pharmacology of these muscles that enable the tentacles to execute complex movements observed during foraging both in naïve and food-conditioned snails. Our findings are also compared as far as possible with earlier and recent data obtained on innervation characteristics and pharmacology of molluscan muscles.


Subject(s)
Mollusca/physiology , Movement/physiology , Muscles/physiology , Receptors, Odorant/physiology , Smell/physiology , Animals , Gastropoda/anatomy & histology , Gastropoda/physiology , Helix, Snails/anatomy & histology , Helix, Snails/metabolism , Helix, Snails/physiology , Mollusca/anatomy & histology , Mollusca/metabolism , Muscles/anatomy & histology , Muscles/innervation , Neurotransmitter Agents/metabolism , Odorants , Receptors, Odorant/metabolism
10.
Biochim Biophys Acta ; 1844(9): 1694-707, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24982030

ABSTRACT

In Proteomics, gene/protein families including both specialized and non-specialized paralogs are an invaluable tool to study the evolution of structure/function relationships in proteins. Metallothioneins (MTs) of the pulmonate gastropod molluscs (snails) offer one of the best materials to study the metal-binding specificity of proteins, because they consist of a polymorphic system that includes members with extremely distinct metal preferences but with a high protein sequence similarity. Cantareus aspersus was the first snail where three paralogous MTs were isolated: the highly specific cadmium (CaCdMT) and copper (CaCuMT) isoforms, and an unspecific CaCd/CuMT isoform, so called because it was natively isolated as a mixed Cd and Cu complex. In this work, we have thoroughly analyzed the Zn(2+)-, Cd(2+)- and Cu(+)-binding abilities of these three CaMTs by means of the spectroscopic and spectrometric characterization of the respective recombinant, as well as in vitro-substituted, metal-complexes. The comparison with the orthologous HpMTs and the study of the isoform-determinant residues allow correlating the protein sequence variability with the coordination capabilities of these MTs. Surprisingly, the CaCuMT isoform exhibits a stronger Cu-thionein character than the HpCuMT ortholog, and the CaCd/CuMT isoform could be defined as a non-optimized Cu-thionein, which has not attained any defined functional differentiation in the framework of the snail MT gene/protein family.


Subject(s)
Cadmium/chemistry , Copper/chemistry , Helix, Snails/chemistry , Metallothionein/chemistry , Amino Acid Sequence , Animals , Cations, Divalent , Cations, Monovalent , Circular Dichroism , Escherichia coli/genetics , Escherichia coli/metabolism , Gene Expression , Helix, Snails/metabolism , Ligands , Metallothionein/metabolism , Molecular Sequence Data , Protein Binding , Protein Isoforms/chemistry , Protein Isoforms/metabolism , Sequence Alignment , Sequence Homology, Amino Acid , Spectrometry, Mass, Electrospray Ionization , Zinc/chemistry
11.
Br J Biomed Sci ; 72(4): 174-81; quiz 208, 2015.
Article in English | MEDLINE | ID: mdl-26738399

ABSTRACT

Research into naturally occurring antimicrobial substances has yielded effective treatments. One area of interest is peptides and proteins produced by invertebrates as part of their defence system, including the contents of mollusc mucus. Mucus produced by the African giant land snail, Achatina fulica has been reported to contain two proteins with broad-spectrum antibacterial activity. Mucus from the brown garden snail, Helix aspersa, appears to have skin regeneration properties. This study sought to investigate the antimicrobial properties of H. aspersa mucus. Mucus was collected from H. aspersa snails, diluted in phosphate-buffered saline (PBS), with the supernatant tested against a wide range of organisms in a disc-diffusion antimicrobial assay. This was followed with comparative experiments involving A. fulica, including bacteriophage assays. Mucus from both species of snail was passed through a series of protein size separation columns in order to determine the approximate size of the antimicrobial substance. Electrophoresis was also carried out on the H. aspersa mucus. Results indicated that H. aspersa mucus had a strong antibacterial effect against several strains of Pseudomonas aeruginosa and a weak effect against Staphylococcus aureus. Mucus from A. fulica also inhibited the growth of S. aureus, but the broad spectrum of activity reported by other workers was not observed. Antimicrobial activity was not caused by bacteriophage. Size separation experiments indicated that the antimicrobial substance(s) in H. aspersa were between 30 and 100 kDa. Electrophoresis revealed two proteins in this region (30-40 kDa and 50-60 kDa). These do not correspond with antimicrobial proteins previously reported in A. fulica. This study found one or more novel antimicrobial agents in H. aspersa mucus, with a strong effect against P. aeruginosa.


Subject(s)
Anti-Infective Agents/pharmacology , Antimicrobial Cationic Peptides/pharmacology , Helix, Snails/metabolism , Mucus/metabolism , Animals , Anti-Infective Agents/chemistry , Anti-Infective Agents/isolation & purification , Antimicrobial Cationic Peptides/chemistry , Antimicrobial Cationic Peptides/isolation & purification , Electrophoresis, Polyacrylamide Gel , Microbial Sensitivity Tests , Molecular Weight , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/growth & development , Staphylococcus aureus/drug effects , Staphylococcus aureus/growth & development
12.
Int J Mol Sci ; 17(1)2015 Dec 22.
Article in English | MEDLINE | ID: mdl-26703589

ABSTRACT

Snail metallothioneins (MTs) constitute an ideal model to study structure/function relationships in these metal-binding polypeptides. Helix pomatia harbours three MT isoforms: the highly specific CdMT and CuMT, and an unspecific Cd/CuMT, which represent paralogous proteins with extremely different metal binding preferences while sharing high sequence similarity. Preceding work allowed assessing that, although, the Cys residues are responsible for metal ion coordination, metal specificity or preference is achieved by diversification of the amino acids interspersed between them. The metal-specific MT polypeptides fold into unique, energetically-optimized complexes of defined metal content, when binding their cognate metal ions, while they produce a mixture of complexes, none of them representing a clear energy minimum, with non-cognate metal ions. Another critical, and so far mostly unexplored, region is the stretch linking the individual MT domains, each of which represents an independent metal cluster. In this work, we have designed and analyzed two HpCdMT constructs with substituted linker segments, and determined their coordination behavior when exposed to both cognate and non-cognate metal ions. Results unequivocally show that neither length nor composition of the inter-domain linker alter the features of the Zn(II)- and Cd(II)-complexes, but surprisingly that they influence their ability to bind Cu(I), the non-cognate metal ion.


Subject(s)
Cadmium/metabolism , Metallothionein/metabolism , Polymorphism, Genetic , Amino Acid Sequence , Animals , Binding Sites , Conserved Sequence , Helix, Snails/genetics , Helix, Snails/metabolism , Metallothionein/chemistry , Metallothionein/genetics , Molecular Sequence Data , Protein Binding , Zinc/metabolism
13.
Bull Exp Biol Med ; 159(2): 192-6, 2015 Jun.
Article in English | MEDLINE | ID: mdl-26085351

ABSTRACT

We studied the involvement of Mζ-like protein kinase (PKMζ) into mechanisms of conditioned food aversion memory reconsolidation in Helix lucorum. Injections PKMζ inhibitor ZIP in a dose of 5 mg/kg on day 2 or 10 after learning led to memory impairment and amnesia development. Injections of the inhibitor in doses of 1.5 or 2.5 mg/kg had no effect. Repeated training on day 11 after induction of amnesia resulted in the formation of memory on the same type of food aversion similar to first training. The number of combinations of conditional (food) and reinforcing (electrical shock) stimuli was similar during initial and repeated training. We hypothesize that the inhibition of Mζ-like protein kinase erases the memory trace and a new memory is formed during repeated training.


Subject(s)
Avoidance Learning/physiology , Conditioning, Classical/physiology , Feeding Behavior/physiology , Helix, Snails/physiology , Memory Consolidation/physiology , Memory, Long-Term/physiology , Protein Kinase C/metabolism , Analysis of Variance , Animals , Electric Stimulation , Helix, Snails/metabolism
14.
Cell Tissue Res ; 358(2): 371-83, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25096715

ABSTRACT

Although glucose is metabolically the most important carbohydrate in almost all living organisms, still little is known about the evolution of the hormonal control of cellular glucose uptake. In this study, we identify Phe-Met-Arg-Phe-amide (FMRFa), also known as molluscan cardioexcitatory tetrapeptide, as a glucose-lowering hormone in the snail Helix aspersa. FMRFa belongs to an evolutionarily conserved neuropeptide family and is involved in the neuron-to-muscle signal transmission in the snail digestive system. This study shows that, beyond this function, FMRFa also has glucose-lowering activity. We found neuronal transcription of genes encoding FMRFa and its receptor and moreover the hemolymph FMRFa levels were peaking at metabolically active periods of the snails. In turn, hypometabolism of the dormant periods was associated with abolished FMRFa production. In the absence of FMRFa, the midintestinal gland ("hepatopancreas") cells were deficient in their glucose uptake, contributing to the development of glucose intolerance. Exogenous FMRFa restored the absorption of hemolymph glucose by the midintestinal gland cells and improved glucose tolerance in dormant snails. We show that FMRFa was released to the hemolymph in response to glucose challenge. FMRFa-containing nerve terminals reach the interstitial sinusoids between the chondroid cells in the artery walls. We propose that, in addition to the known sites of possible FMRFa secretion, these perivascular sinusoids serve as neurohemal organs and allow FMRFa release. This study suggests that in evolution, not only the insulin-like peptides have adopted the ability to increase cellular glucose uptake and can act as hypoglycemic hormones.


Subject(s)
FMRFamide/metabolism , Glucose/metabolism , Helix, Snails/metabolism , Animals , Glucose Tolerance Test , Hemolymph/metabolism , Intestinal Mucosa/metabolism , Intestines/ultrastructure , Lipid Metabolism , Models, Biological
15.
J Biol Inorg Chem ; 19(6): 923-35, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24687203

ABSTRACT

The Helix pomatia metallothionein (MT) system, namely, its two highly specific forms, HpCdMT and HpCuMT, has offered once again an optimum model to study metal-protein specificity. The present work investigates the most unexplored aspect of the coordination behavior of MT polypeptides with respect to either cognate or noncognate metal ions, as opposed to the standard studies of cognate metal ion coordination. To this end, we analyzed the in vivo synthesis of the corresponding complexes with their noncognate metals, and we performed a detailed spectroscopic and spectrometric study of the Zn(2+)/Cd(2+) and Zn(2+)/Cu(+) in vitro replacement reactions on the initial Zn-HpMT species. An HpCuMTAla site-directed mutant, exhibiting differential Cu(+)-binding abilities in vivo, was also included in this study. We demonstrate that when an MT binds its cognate metal, it yields well-folded complexes of limited stoichiometry, representative of minimal-energy conformations. In contrast, the incorporation of noncognate metal ions is better attributed to an unspecific reaction of cysteinic thiolate groups with metal ions, which is dependent on their concentration in the surrounding milieu, where no minimal-energy structure is reached, and otherwise, the MT peptide acts as a multidentate ligand that will bind metal ions until its capacity has been saturated. Additionally, we suggest that previous binding of an MT polypeptide with its noncognate metal ion (e.g., binding of Zn(2+) to the HpCuMT isoform) may preclude the correct folding of the complex with its cognate metal ion.


Subject(s)
Cadmium/metabolism , Copper/metabolism , Helix, Snails/metabolism , Metallothionein/metabolism , Models, Biological , Zinc/metabolism , Amino Acid Sequence , Animals , Cadmium/chemistry , Copper/chemistry , Helix, Snails/chemistry , Metallothionein/chemistry , Molecular Sequence Data , Protein Isoforms/chemistry , Protein Isoforms/metabolism , Sequence Alignment , Zinc/chemistry
16.
Bull Environ Contam Toxicol ; 93(5): 526-31, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25112435

ABSTRACT

The objectives of this study were (1) to determine cadmium (Cd) accumulation in the midgut gland of a land snail Helix pomatia L. inhabiting residential areas of the 14 largest cities in Poland, and (2) to examine whether the accumulated Cd exerted any toxic effects. The average accumulation of Cd in the midgut gland of snails, weighing 16-18 g, ranged from 7.00 to 87.3 µg/g dry weight (0.06-0.77 µmol/g) and differed significantly among animals from the various urban areas. This difference in Cd accumulation was not related to city population, but was associated with the topsoil Cd (R(2) = 0.868, p < 0.0001). The tissue Cd was not found to produce toxicity (histopathology, programmed cell death, lipofuscin formation or lipid peroxidation), probably due to the induction of sufficiently high quantities of metallothionein and glutathione, well-known protective molecules.


Subject(s)
Cadmium/metabolism , Cadmium/toxicity , Cities , Digestive System/drug effects , Digestive System/metabolism , Helix, Snails/metabolism , Animals , Cell Death/drug effects , Digestive System/cytology , Ecotoxicology , Environmental Monitoring , Environmental Pollutants/metabolism , Environmental Pollutants/toxicity , Glutathione/metabolism , Helix, Snails/drug effects , Lipid Peroxidation/drug effects , Metallothionein/metabolism , Poland , Soil/chemistry
17.
Article in English | MEDLINE | ID: mdl-39236428

ABSTRACT

This work for the first time reported the complete transformation of 17ß-estradiol (E2) to estrone (E1) by unknown wild-type enzyme present in the widely used commercial arylsulfatase derived from Helix pomatia. It was found that acetate could effectively inhibit the unknown enzyme with a half inhibitory concentration (IC50) of 140.9 µM, while phosphate and citrate showed no inhibition. Since the buffer solutions with phosphate and citrate have been used in the enzymatic hydrolysis of natural estrogen conjugates for decades, the transformation of E2 to E1 likely occurred during such procedure, inevitably leading to overestimated E1, but underestimated E2. It was further suggested that acetate should be used to prevent this undesirable transformation during the enzymatic hydrolysis of natural estrogen conjugates.


Subject(s)
Arylsulfatases , Estradiol , Estrone , Helix, Snails , Estrone/chemistry , Estrone/metabolism , Estradiol/chemistry , Estradiol/metabolism , Helix, Snails/enzymology , Helix, Snails/metabolism , Helix, Snails/chemistry , Arylsulfatases/metabolism , Arylsulfatases/chemistry , Arylsulfatases/genetics , Animals
18.
Article in English | MEDLINE | ID: mdl-23474253

ABSTRACT

The strong dependence of metabolic rates on body mass has attracted the interest of ecological physiologists, as it has important implications to many aspects of biology including species variations in body size, the evolution of life history, and the structure and function of biological communities. The great diversity of observed scaling exponents has led some authors to conclude that there is no single universal scaling exponent, but instead it ranges from 2/3 to 1. Most of the telling evidence against the universality of power scaling exponents comes from ontogenetic changes. Nevertheless, there could be other sources of phenotypic variation that influence this allometric relationship at least at the intraspecific level. In order to explore the general concept of the metabolic scaling in terrestrial molluscs we tested the role of several biological and methodological sources of variation on the empirically estimated scaling exponent. Specifically, we measured a proxy of metabolic rate (CO(2) production) in 421 individuals, during three generations, in three different populations. Additionally, we measured this scaling relationship in 208 individuals at five developmental stages. Our results suggest that the metabolic scaling exponent at the intraspecific level does not have a single stationary value, but instead it shows some degree of variation across geographic distribution, transgenerational change and ontogenetic stages. The major differences in the metabolic scaling exponent that we found were at different developmental stages of snails, because ontogeny involves increases in size at different rates, which in turn, generate differential energy demands.


Subject(s)
Ecosystem , Energy Metabolism , Helix, Snails/metabolism , Helix, Snails/physiology , Animals , Body Size/physiology , Carbon Dioxide/metabolism , Chile , Geography , Helix, Snails/classification , Models, Biological , Oxygen Consumption/physiology , Species Specificity
19.
Ecotoxicol Environ Saf ; 95: 91-7, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23756058

ABSTRACT

The in vivo sublethal toxic effects (0.2 and 0.6 LD50) of topically applied imidacloprid on biochemical biomarkers in the land snail, Helix aspersa was examined. Biochemical perturbations were assessed by measuring the three enzymatic (Acetylcholinesterase, AChE; catalase, CAT and glutathione-S-transferase, GST) activities and three energy reserves (protein, glycogen and lipids) in the snails. Snail samples were taken from each sublethal dose and control groups at 1, 3 and 7 days after treatment. The results revealed that there were overall decrease in AChE activity as well as depletion of lipids and glycogen contents in the imidacloprid-treated snails compared to control groups. The CAT and GST activities of treated snails with the sublethal doses of imidacloprid were significantly higher than those of untreated controls along the three times of exposure. Moreover, an increase in the level of total proteins was observed in animals treated with 0.6 LD50 imidacloprid compared to control groups. The alterations in all tested biochemical perturbations were most pronounced with the 0.6 LD50 than 0.2 LD50. This study suggests that alterations of the enzyme activities and energy reserves in this species that could be useful as biomarkers of imidacloprid exposure in the evaluation of terrestrial impacts of this insecticide.


Subject(s)
Helix, Snails/drug effects , Imidazoles/toxicity , Insecticides/toxicity , Nitro Compounds/toxicity , Acetylcholinesterase/metabolism , Animals , Biomarkers/metabolism , Catalase/metabolism , Energy Metabolism/drug effects , Glutathione Transferase/metabolism , Glycogen/metabolism , Helix, Snails/metabolism , Lipid Metabolism , Neonicotinoids
20.
J Biol Chem ; 286(23): 20260-6, 2011 Jun 10.
Article in English | MEDLINE | ID: mdl-21372134

ABSTRACT

Helix pomatia agglutinin (HPA), the lectin from the albumen gland of the Roman snail, has been used in histochemical studies relating glycosylation changes to the metastatic potential of solid tumors. To facilitate the use of HPA in a clinical (diagnostic) setting, detailed analysis of the lectin, including cloning and recombinant production of HPA, is required. A combination of isoelectric focusing, amino acid sequence analysis, and cloning revealed two polypeptides in native HPA preparations (HPAI and HPAII), both consistent with GalNAc-binding lectins of the H-type family. Pairwise sequence alignment showed that HPAI and HPAII share 54% sequence identity whereas molecular modeling using SWISS-MODEL suggests they are likely to adopt similar tertiary structure. The inherent heterogeneity of native HPA highlighted the need for production of functional recombinant protein; this was addressed by preparing His-thioredoxin-tagged fusion products in Escherichia coli Rosetta-gami B (DE3) cells. The recombinant lectins agglutinated human blood group A erythrocytes whereas their oligosaccharide specificity, evaluated using glycan microarrays, showed that they predominantly bind glycans with terminal α-GalNAc residues. Surface plasmon resonance with immobilized GalNAc-BSA confirmed that recombinant HPAI and HPAII bind strongly with this ligand (K(d) = 0.60 nm and 2.00 nm, respectively) with a somewhat higher affinity to native HPA (K(d) = 7.67 nm). Recombinant HPAII also bound the breast cancer cells of breast cancer tissue specimens in a manner similar to native lectin. The recombinant HPA described here shows important potential for future studies of cancer cell glycosylation and as a reagent for cancer prognostication.


Subject(s)
Exocrine Glands/chemistry , Helix, Snails/chemistry , Helix, Snails/genetics , Receptors, N-Acetylglucosamine/chemistry , Receptors, N-Acetylglucosamine/genetics , ABO Blood-Group System/chemistry , ABO Blood-Group System/genetics , ABO Blood-Group System/metabolism , Animals , Cloning, Molecular , Exocrine Glands/metabolism , Helix, Snails/metabolism , Humans , Protein Binding , Receptors, N-Acetylglucosamine/metabolism , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism
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