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Bioactive and structural metabolites of pseudomonas and burkholderia species causal agents of cultivated mushrooms diseases.

Andolfi A, Cimmino A, Cantore PL, Iacobellis NS, Evidente A - Perspect Medicin Chem (2008)

Bottom Line: In particular, their antimicrobial activity and the alteration of biological and model membranes (red blood cell and liposomes) was established.In the case of tolaasin I interaction with membranes was also related to the tridimensional structure in solution as determined by NMR combined with molecular dynamic calculation techniques.The isolation and structure determination of bioactive metabolites produced by B. gladioli pv. agaricicola are still in progress but preliminary results indicate their peptide nature.

View Article: PubMed Central - PubMed

Affiliation: Dipartimento di Scienze del Suolo, della Pianta, dell'Ambiente e delle Produzioni Animali, Università di Napoli Federico II, Via Università 100, 80055 Portici, Italy.

ABSTRACT
Pseudomonas tolaasii, P. reactans and Burkholderia gladioli pv. agaricicola, are responsible of diseases on some species of cultivated mushrooms. The main bioactive metabolites produced by both Pseudomonas strains are the lipodepsipeptides (LDPs) tolaasin I and II and the so called White Line Inducing Principle (WLIP), respectively, LDPs which have been extensively studied for their role in the disease process and for their biological properties. In particular, their antimicrobial activity and the alteration of biological and model membranes (red blood cell and liposomes) was established. In the case of tolaasin I interaction with membranes was also related to the tridimensional structure in solution as determined by NMR combined with molecular dynamic calculation techniques. Recently, five news minor tolaasins, tolaasins A-E, were isolated from the culture filtrates of P. tolaasii and their chemical structure was determined by extensive use of NMR and MS spectroscopy. Furthermore, their antimicrobial activity was evaluated on target micro-organisms (fungi-including the cultivated mushrooms Agaricus bisporus, Lentinus edodes, and Pleurotus spp.-chromista, yeast and bacteria). The Gram positive bacteria resulted the most sensible and a significant structure-activity relationships was apparent. The isolation and structure determination of bioactive metabolites produced by B. gladioli pv. agaricicola are still in progress but preliminary results indicate their peptide nature. Furthermore, the exopolysaccharide (EPS) from the culture filtrates of B. gladioli pv. agaricicola, as well as the O-chain and lipid A, from the lipopolysaccharide (LPS) of the three bacteria, were isolated and the structures determined.

No MeSH data available.


Related in: MedlinePlus

Differential spectra after H/D exchange of the WLIP amide protons: Analysis of differences in the amide I band of films of WLIP samples deposited from a buffer solution (B, dashed line), TFE (T, dotted line), HFIP (H, solid line), SDS (S, thick dashed line) and after binding to the lipid membrane (L, thick dotted-dashed line). Differential spectra were obtained by subtracting the hydrogenated spectra of WLIP in the different environments from the corresponding deuterated spectra. (Inset) Area of negative peaks between 1710 and 1660 cm−1. All the differences are between normalized spectra, i.e. with the amide I’ peak area set at 1.
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f14-pmc-2008-081: Differential spectra after H/D exchange of the WLIP amide protons: Analysis of differences in the amide I band of films of WLIP samples deposited from a buffer solution (B, dashed line), TFE (T, dotted line), HFIP (H, solid line), SDS (S, thick dashed line) and after binding to the lipid membrane (L, thick dotted-dashed line). Differential spectra were obtained by subtracting the hydrogenated spectra of WLIP in the different environments from the corresponding deuterated spectra. (Inset) Area of negative peaks between 1710 and 1660 cm−1. All the differences are between normalized spectra, i.e. with the amide I’ peak area set at 1.

Mentions: The rigidity of WLIP, cyclized via lactone formation between the third and the C-terminal residues (Mortishire-Smith et al. 1991b), could explain the slight variation observed in the amide I’ spectrum even after the interaction with the membrane. Moreover, the presence in the same molecule of unusual residues made the assignment of a secondary structure to the curve fitting components more difficult. Therefore the differential spectra obtained after H/D exchange or after the buffer substitution with a membrane-like environment were focused (Fig. 14). In fact, variations of spectra after H/D exchange provided information about the local structure of the molecule. The decrease of absorption at 1670 cm−1 (and the corresponding increment at 1634 cm−1), for example, indicated the presence of free protons (i.e. not involved in hydrogen bonds) which were able to exchange with deuterium, probably because of their good accessibility allowed by the local structure of the molecule. This behaviour could be attributed to a turn configuration with fast exchanging protons. Interestingly, this behaviour was dependent on the solvent used and decreased in a lipid-mimetic environment (effect measured by the small negative and positive peaks at 1670 cm−1 and 1634 cm−1, respectively), suggesting a decrease of the proton accessibility and, consequently, a change in the local structure of the molecule (Fig. 15A). Therefore, it seemed that the lipid-mimetic conditions enhanced the formation of hydrogen bonds inside the structure which become less susceptible to deuteration. Similar changes were confirmed in differential spectra obtained by subtracting the deuterated spectrum of the soluble form in buffer from those obtained with other solvents (Fig. 15B). Variations in the absorption at the above wavenumbers showed an increment at 1670 cm−1 and a corresponding decrease at 1634 cm−1 with the maximum in the lipid membrane. These changes favoured a more stable local structure which was enhanced from the lipid-mimetic environments and that could be able to interact with the membrane and its hydrophobic moiety. In addition, the disordering effect on the vesicles membrane induced by the WLIP binding supports the hypothesis of an insertion of the molecule into the membrane lipid core.


Bioactive and structural metabolites of pseudomonas and burkholderia species causal agents of cultivated mushrooms diseases.

Andolfi A, Cimmino A, Cantore PL, Iacobellis NS, Evidente A - Perspect Medicin Chem (2008)

Differential spectra after H/D exchange of the WLIP amide protons: Analysis of differences in the amide I band of films of WLIP samples deposited from a buffer solution (B, dashed line), TFE (T, dotted line), HFIP (H, solid line), SDS (S, thick dashed line) and after binding to the lipid membrane (L, thick dotted-dashed line). Differential spectra were obtained by subtracting the hydrogenated spectra of WLIP in the different environments from the corresponding deuterated spectra. (Inset) Area of negative peaks between 1710 and 1660 cm−1. All the differences are between normalized spectra, i.e. with the amide I’ peak area set at 1.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2746572&req=5

f14-pmc-2008-081: Differential spectra after H/D exchange of the WLIP amide protons: Analysis of differences in the amide I band of films of WLIP samples deposited from a buffer solution (B, dashed line), TFE (T, dotted line), HFIP (H, solid line), SDS (S, thick dashed line) and after binding to the lipid membrane (L, thick dotted-dashed line). Differential spectra were obtained by subtracting the hydrogenated spectra of WLIP in the different environments from the corresponding deuterated spectra. (Inset) Area of negative peaks between 1710 and 1660 cm−1. All the differences are between normalized spectra, i.e. with the amide I’ peak area set at 1.
Mentions: The rigidity of WLIP, cyclized via lactone formation between the third and the C-terminal residues (Mortishire-Smith et al. 1991b), could explain the slight variation observed in the amide I’ spectrum even after the interaction with the membrane. Moreover, the presence in the same molecule of unusual residues made the assignment of a secondary structure to the curve fitting components more difficult. Therefore the differential spectra obtained after H/D exchange or after the buffer substitution with a membrane-like environment were focused (Fig. 14). In fact, variations of spectra after H/D exchange provided information about the local structure of the molecule. The decrease of absorption at 1670 cm−1 (and the corresponding increment at 1634 cm−1), for example, indicated the presence of free protons (i.e. not involved in hydrogen bonds) which were able to exchange with deuterium, probably because of their good accessibility allowed by the local structure of the molecule. This behaviour could be attributed to a turn configuration with fast exchanging protons. Interestingly, this behaviour was dependent on the solvent used and decreased in a lipid-mimetic environment (effect measured by the small negative and positive peaks at 1670 cm−1 and 1634 cm−1, respectively), suggesting a decrease of the proton accessibility and, consequently, a change in the local structure of the molecule (Fig. 15A). Therefore, it seemed that the lipid-mimetic conditions enhanced the formation of hydrogen bonds inside the structure which become less susceptible to deuteration. Similar changes were confirmed in differential spectra obtained by subtracting the deuterated spectrum of the soluble form in buffer from those obtained with other solvents (Fig. 15B). Variations in the absorption at the above wavenumbers showed an increment at 1670 cm−1 and a corresponding decrease at 1634 cm−1 with the maximum in the lipid membrane. These changes favoured a more stable local structure which was enhanced from the lipid-mimetic environments and that could be able to interact with the membrane and its hydrophobic moiety. In addition, the disordering effect on the vesicles membrane induced by the WLIP binding supports the hypothesis of an insertion of the molecule into the membrane lipid core.

Bottom Line: In particular, their antimicrobial activity and the alteration of biological and model membranes (red blood cell and liposomes) was established.In the case of tolaasin I interaction with membranes was also related to the tridimensional structure in solution as determined by NMR combined with molecular dynamic calculation techniques.The isolation and structure determination of bioactive metabolites produced by B. gladioli pv. agaricicola are still in progress but preliminary results indicate their peptide nature.

View Article: PubMed Central - PubMed

Affiliation: Dipartimento di Scienze del Suolo, della Pianta, dell'Ambiente e delle Produzioni Animali, Università di Napoli Federico II, Via Università 100, 80055 Portici, Italy.

ABSTRACT
Pseudomonas tolaasii, P. reactans and Burkholderia gladioli pv. agaricicola, are responsible of diseases on some species of cultivated mushrooms. The main bioactive metabolites produced by both Pseudomonas strains are the lipodepsipeptides (LDPs) tolaasin I and II and the so called White Line Inducing Principle (WLIP), respectively, LDPs which have been extensively studied for their role in the disease process and for their biological properties. In particular, their antimicrobial activity and the alteration of biological and model membranes (red blood cell and liposomes) was established. In the case of tolaasin I interaction with membranes was also related to the tridimensional structure in solution as determined by NMR combined with molecular dynamic calculation techniques. Recently, five news minor tolaasins, tolaasins A-E, were isolated from the culture filtrates of P. tolaasii and their chemical structure was determined by extensive use of NMR and MS spectroscopy. Furthermore, their antimicrobial activity was evaluated on target micro-organisms (fungi-including the cultivated mushrooms Agaricus bisporus, Lentinus edodes, and Pleurotus spp.-chromista, yeast and bacteria). The Gram positive bacteria resulted the most sensible and a significant structure-activity relationships was apparent. The isolation and structure determination of bioactive metabolites produced by B. gladioli pv. agaricicola are still in progress but preliminary results indicate their peptide nature. Furthermore, the exopolysaccharide (EPS) from the culture filtrates of B. gladioli pv. agaricicola, as well as the O-chain and lipid A, from the lipopolysaccharide (LPS) of the three bacteria, were isolated and the structures determined.

No MeSH data available.


Related in: MedlinePlus