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Thomas Rohrlack - One of the best experts on this subject based on the ideXlab platform.
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the red queen race between parasitic chytrids and their host planktothrix a test using a time series reconstructed from sediment dna
PLOS ONE, 2015Co-Authors: Marcia Kyle, Sigrid Haande, Veronika Ostermaier, Thomas RohrlackAbstract:Parasitic chytrid fungi (phylum Chytridiomycota) are known to infect specific phytoplankton, including the filamentous cyanobacterium Planktothrix. Subspecies, or chemotypes of Planktothrix can be identified by the presence of characteristic Oligopeptides. Some of these Oligopeptides can be associated with important health concerns due to their potential for toxin production. However, the relationship between chytrid parasite and Planktothrix host is not clearly understood and more research is needed. To test the parasite - host relationship over time, we used a sediment core extracted from a Norwegian lake known to contain both multiple Planktothrix chemotype hosts and their parasitic chytrid. Sediment DNA of chytrids and Planktothrix was amplified and a 35-year coexistence was found. It is important to understand how these two antagonistic species can coexistence in a lake. Reconstruction of the time series showed that between 1979–1990 at least 2 strains of Planktothrix were present and parasitic pressure exerted by chytrids was low. After this period one chemotype became dominant and yet showed continued low susceptibility to chytrid parasitism. Either environmental conditions or intrinsic characteristics of Planktothrix could have been responsible for this continued dominance. One possible explanation could be found in the shift of Planktothrix to the metalimnion, an environment that typically consists of low light and decreased temperatures. Planktothrix are capable of growth under these conditions while the chytrid parasites are constrained. Another potential explanation could be due to the differences between cellular Oligopeptide variations found between Planktothrix chemotypes. These Oligopeptides can function as defense systems against chytrids. Our findings suggest that chytrid driven diversity was not maintained over time, but that the combination of environmental constraints and multiple Oligopeptide production to combat chytrids could have allowed one Planktothrix chemotype to have dominance despite chytrid presence.
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putative antiparasite defensive system involving ribosomal and nonribosomal Oligopeptides in cyanobacteria of the genus planktothrix
Applied and Environmental Microbiology, 2013Co-Authors: Thomas Rohrlack, Guntram Christiansen, Rainer KurmayerAbstract:Parasitic chytrid fungi can inflict significant mortality on cyanobacteria but frequently fail to keep cyanobacterial dominance and bloom formation in check. Our study tested whether Oligopeptide production, a common feature in many cyanobacteria, can be a defensive mechanism against chytrid parasitism. The study employed the cyanobacterial strain Planktothrix NIVA-CYA126/8 and its mutants with knockout mutations for microcystins, anabaenopeptins, and microviridins, major Oligopeptide classes to be found in NIVA-CYA126/8. Four chytrid strains were used as parasite models. They are obligate parasites of Planktothrix and are unable to exploit alternative food sources. All chytrid strains were less virulent to the NIVA-CYA126/8 wild type than to at least one of its Oligopeptide knockout mutants. One chytrid strain even failed to infect the wild type, while exhibiting considerable virulence to all mutants. It is therefore evident that producing microcystins, microviridins, and/or anabaenopeptins can reduce the virulence of chytrids to Planktothrix, thereby increasing the host's chance of survival. Microcystins and anabaenopeptins are nonribosomal Oligopeptides, while microviridins are produced ribosomally, suggesting that Planktothrix resists chytrids by relying on metabolites that are produced via distinct biosynthetic pathways. Chytrids, on the other hand, can adapt to the Oligopeptides produced by Planktothrix in different ways. This setting most likely results in an evolutionary arms race, which would probably lead to Planktothrix and chytrid population structures that closely resemble those actually found in nature. In summary, the findings of the present study suggest Oligopeptide production in Planktothrix to be part of a defensive mechanism against chytrid parasitism.
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possible implications of chytrid parasitism for population subdivision in freshwater cyanobacteria of the genus planktothrix
Applied and Environmental Microbiology, 2011Co-Authors: Jorn Henrik Sonstebo, Thomas RohrlackAbstract:The coexistence of conspecific lineages within a given population is a common trait in many microorganisms. In cyanobacteria, such population subdivision is not well understood. Specifically, the mechanisms that cause cyanobacteria to differentiate or to maintain homogeneity are far from established. Population subdivision is best studied in the picocyanobacteria Synechococcus and Prochlorococcus (4, 21, 32), which show niche partitioning among ecotypes, thought to occur at a comparatively low level of 16S rRNA gene sequence similarity (95 to 97%). The coexistence of genetically distinct lineages was also found in populations of more complex cyanobacteria (3, 14, 25). Most authors proposed abiotic factors as the driving force of cyanobacterial subpopulation evolution and dynamics. Recently, we reported population subdivision in the filamentous freshwater cyanobacterium Planktothrix at a level of >99% 16S rRNA gene sequence similarity (35, 36). Due to differences in rates of occurrence and sequences of genes encoding nonribosomal and ribosomal Oligopeptide synthesis, strains of Planktothrix may posses distinct cellular patterns of Oligopeptides (38, 49). This allows delimitation of Oligopeptide chemotypes, henceforth referred to as chemotypes. A field study in Norwegian Lake Steinsfjorden identified four coexisting Planktothrix chemotypes that differed considerably in seasonal dynamics, depth distribution, and participation in loss processes (35). Shifts in the relative chemotype composition occurred periodically and started with a significant loss of biomass of one chemotype, followed by the growth of others. There was no correlation between temperature or the availability of light, the amount of phosphorus or nitrogen, and the relative chemotype composition of the local Planktothrix population. A second study identified the same chemotypes in six Norwegian and two Finnish lakes of vastly dissimilar nutrient loadings and morphologies (36), implying once again that the chemotype composition of Planktothrix populations is not controlled by abiotic conditions. On the basis of the above findings, we proposed a top-down approach to explain chemotype evolution and dynamics; i.e., we suggested that chemotypes are functional groups that form in response to and that are controlled by biotic factors causing loss of Planktothrix biomass rather than abiotic factors controlling its growth (36). A follow-up on this hypothesis appears to be worthwhile in several respects. Oligopeptides and chemotypes occur throughout the phylum of cyanobacteria (49). Knowledge on Planktothrix chemotype evolution and dynamics may therefore be generalizable and may provide insights into the yet unknown function of cyanobacterial Oligopeptide production. Studies on cyanobacterial population subdivision often focus on abiotic conditions, although ecological considerations call for a broader view (42). The well-defined Planktothrix chemotypes provide a promising model for investigating the role of biotic loss processes in cyanobacterial population subdivision. The formation of long filaments largely protects Planktothrix against generalist grazers (29). The implications of biotic factors for cyanobacterial population subdivision can therefore be studied in a simple setting where only a limited number of specialized grazers and parasites play a role. One group of specialized parasites, the parasitic chytrid fungi, is commonly believed to inflict significant mortality on numerous types of organisms, including Planktothrix (8, 13, 40), but is nevertheless virtually overlooked by present-day research on cyanobacterial ecology. The parasitic potency of chytrid fungi is proven most impressively by the disease chytridiomycosis, which threatens amphibian diversity at a global scale (15). Early studies on chytrid-cyanobacteria interrelations suggested that chytrid fungi have narrow host ranges, usually encompassing only one or a few related species, and that there is a chytrid to most if not all cyanobacteria (41). In nature, chytrid infection of cyanobacteria is considered omnipresent (33). Chytrid fungi form zoospores that employ a flagellum and probably chemotaxis to find their hosts (17). In the case of chytrid fungi infecting Planktothrix, the zoospore encysts at the surface of a suitable host and penetrates it and the walls between neighboring cells of the same filament by forming a rhizoid of up to 150 μg in length (8). Host cells are digested by release of extracellular enzymes from the rhizoid (17), most likely including serine proteases of the trypsin and chymotrypsin types (44). Later, a sporangium is formed, in which new zoospores are produced. The way in which chytrid fungi live suggests a link between Planktothrix chemotype performance in nature and chytrid parasitism. Many of the more than 600 known Oligopeptides produced by cyanobacteria and used here to define Planktothrix chemotypes are potent inhibitors of serine proteases, such as chymotrypsin and trypsin (37), and may therefore interfere with proteases released by chytrid fungi during rhizoid formation and growth. Other Oligopeptides are potentially toxic to eukaryotes in general (9). Such compounds may suppress chytrid infection at almost any stage. Due to distinct cellular Oligopeptide patterns of Planktothrix chemotypes, the outcome of chytrid parasitism may well be chemotype dependent, which would provide a possible explanation for the distinct behavior of Planktothrix chemotypes in nature. Furthermore, the subdivision of Planktothrix populations into chemotypes may be a consequence of coevolution between Planktothrix and parasitic chytrid fungi. Here we provide a laboratory test of whether chytrid parasitism can, in principle, be a driving force of Planktothrix population subdivision into chemotypes and chemotype dynamics. We test whether (i) chytrid parasitism is chemotype dependent, (ii) the parasitic potency of chytrid fungi is strong enough to exert significant selective pressure at the chemotype level, (iii) chytrid fungi can differ in their chemotype preferences, (iv) chytrid fungi have a host range that is narrow enough to result in coevolution with Planktothrix only, and (v) chytrid fungi with different chemotype preferences coexist in nature.
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distribution of Oligopeptide chemotypes of the cyanobacterium planktothrix and their persistence in selected lakes in fennoscandia 1
Journal of Phycology, 2009Co-Authors: Thomas Rohrlack, Randi Skulberg, Olav M SkulbergAbstract:Eighty-seven Planktothrix (Anagnostidis and Komarek 1988) strains isolated from 13 lakes in Scandinavia and Finland between 1964 and 2007 were screened for Oligopeptides. Forty-six individual compounds were detected in total, belonging to the structural classes anabaenopeptins (six variants), aeruginosins (six variants), cyanopeptolins (21 variants), microcystins (five variants), microginins (two variants), and microviridins (two variants). Oscillatorin was also found. Three additional compounds could not be assigned to known Oligopeptide classes. Thirty Oligopeptides have not been described in previous studies. Of these new compounds, five were aeruginosins and 20 cyanopeptolins. The number of Oligopeptides per strain ranged from one to 13. No Oligopeptide-free strains were found, suggesting that Oligopeptide production is vital for Planktothrix. On the basis of their Oligopeptide patterns, the Planktothrix strains of the present study were assigned to 17 chemotypes. Three major chemotypes occurred in up to six lakes. One chemotype occurred in lakes around the city of Oslo (Norway), on the Finnish island Fasta Aland, which is situated in the Baltic Sea, and on the Finnish mainland. This wide distribution suggests that chemotypes can be subjects of recurrent dispersal and/or strong directional selection. Lake size, maximum depth, and nutrient availability appeared to be of minor importance for the ability of some chemotypes to colonize a water body successfully as long as the general requirements of Planktothrix were met. Four chemotypes were reisolated from the Oslo lake district over a period of 33–40 years, suggesting that they have been members of local Planktothrix populations for decades.
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Oligopeptide chemotypes of the toxic freshwater cyanobacterium planktothrix can form sub populations with dissimilar ecological traits
Limnology and Oceanography, 2008Co-Authors: Thomas Rohrlack, Camilla Blikstad Halstvedt, Robert Ptacnik, Randi Skulberg, Hans Utkilen, Bente Edvardsen, Olav M SkulbergAbstract:Nonribosomal Oligopeptides were used as qualitative and quantitative markers to test whether populations of the toxic freshwater cyanobacterium Planktothrix comprise subpopulations with dissimilar ecological traits. A field program was conducted in Lake Steinsfjorden (Norway), where Planktothrix has dominated the phytoplankton community for decades, allowing the present study to disregard other potential producers of nonribosomal Oligopeptides. Four chemotypes with distinct cellular Oligopeptide patterns were found in the lake. The chemotypes occurred largely unaltered throughout a period of up to 33 yr and differed with respect to seasonal dynamics, depth distribution, and participation in loss processes. Changes in the relative abundance of chemotypes occurred almost constantly and could not be explained with fluctuations in light, temperature, or concentration of macronutrients but might have been due to differences among chemotypes in depth regulation or interaction with grazers or pathogens. Chemotypes correlated weakly with taxonomic groups and genotypes defined on the basis of phycocyanin operon deoxyribonucleic acid (DNA) sequences. Our findings suggest that first, Oligopeptide chemotypes can have dissimilar ecological traits and therefore interact differently with their environment; second, populations of toxic freshwater cyanobacteria can comprise multiple ecologically distinct subpopulations; and, third, the relative abundance of these may vary, causing a high variability in wholepopulation properties. The latter was demonstrated for the microcystin-related toxicity of Planktothrix. The consequences of the present findings for the taxonomy of Planktothrix are discussed.
Cordelia Schienefischer - One of the best experts on this subject based on the ideXlab platform.
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peptidyl prolyl cis trans isomerases comparative reactivities of cyclophilins fk506 binding proteins and parvulins with fluorinated Oligopeptide and protein substrates
Biochemistry, 2005Co-Authors: Ralph Golbik, Elisabeth Weyherstingl, Robert Huber, Luis Moroder, Nediljko Budisa, Cordelia SchienefischerAbstract:Peptidyl prolyl cis/trans-isomerases catalyze the cis−trans isomerization of prolyl bonds in Oligopeptides and various folding states of proteins. The proline residue in PPIase substrates at the P1‘ subsite, which follows the isomerizing peptide bond, appears to be the common recognition element for all subfamilies of this enzyme class. The molecular principles that govern substrate specificity at the P1‘ subsite were analyzed using 4-fluoroproline-containing tetrapeptide 4-nitroanilides and barstar Cys40Ala/Cys82Ala/Pro27Ala/Pro48→4-fluoroproline quadruple variants. Generally, PPIase catalysis demonstrated stereospecificity for monofluoro substitutions at the 4-position of the pyrrolidine ring. However, the replacement of hydrogens with fluoro atoms did not impair productive interactions for the majority of PPIase−substrate complexes. Comparison of specificity constants for Oligopeptide and protein substrates revealed striking differences in the 4-fluoroproline substituent effects between members of the ...
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peptidyl prolyl cis trans isomerases comparative reactivities of cyclophilins fk506 binding proteins and parvulins with fluorinated Oligopeptide and protein substrates
Biochemistry, 2005Co-Authors: Ralph Golbik, Elisabeth Weyherstingl, Robert Huber, Luis Moroder, Nediljko Budisa, Cordelia SchienefischerAbstract:Peptidyl prolyl cis/trans-isomerases catalyze the cis-trans isomerization of prolyl bonds in Oligopeptides and various folding states of proteins. The proline residue in PPIase substrates at the P1' subsite, which follows the isomerizing peptide bond, appears to be the common recognition element for all subfamilies of this enzyme class. The molecular principles that govern substrate specificity at the P1' subsite were analyzed using 4-fluoroproline-containing tetrapeptide 4-nitroanilides and barstar Cys40Ala/Cys82Ala/Pro27Ala/Pro48-->4-fluoroproline quadruple variants. Generally, PPIase catalysis demonstrated stereospecificity for monofluoro substitutions at the 4-position of the pyrrolidine ring. However, the replacement of hydrogens with fluoro atoms did not impair productive interactions for the majority of PPIase-substrate complexes. Comparison of specificity constants for Oligopeptide and protein substrates revealed striking differences in the 4-fluoroproline substituent effects between members of the PPIase families. Introduction of 4(R)-fluoroproline resulted in an Oligopeptide substrate completely resistant to catalytic effects of FKBP-like PPIases. By contrast, the 4(R)-fluoroproline barstar variant demonstrated only slightly reduced or even better catalytic susceptibility when compared to the parent barstar Cys40Ala/Cys82Ala/Pro27Ala/Pro48 substrate. On the other hand, Suc-Ala-Ser-4(S)-FPro-Phe-pNA exhibits a discriminating specificity toward the prototypic parvulin, the Escherichia coli Par10. The E. coli trigger factor, in the extreme, catalyzes Cys40Ala/Cys82Ala/Pro27Ala/4-F(2)Pro48 with a more than 20-fold higher efficiency when compared to the proline-containing congener. These findings support the combined subsite concept for PPIase catalysis in which the positioning of a substrate in the active cleft must activate a still unknown number of remote subsites in the transition state of the reaction. The number of critical subsites was shown to vary between the PPIase families.
Ralph Golbik - One of the best experts on this subject based on the ideXlab platform.
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peptidyl prolyl cis trans isomerases comparative reactivities of cyclophilins fk506 binding proteins and parvulins with fluorinated Oligopeptide and protein substrates
Biochemistry, 2005Co-Authors: Ralph Golbik, Elisabeth Weyherstingl, Robert Huber, Luis Moroder, Nediljko Budisa, Cordelia SchienefischerAbstract:Peptidyl prolyl cis/trans-isomerases catalyze the cis−trans isomerization of prolyl bonds in Oligopeptides and various folding states of proteins. The proline residue in PPIase substrates at the P1‘ subsite, which follows the isomerizing peptide bond, appears to be the common recognition element for all subfamilies of this enzyme class. The molecular principles that govern substrate specificity at the P1‘ subsite were analyzed using 4-fluoroproline-containing tetrapeptide 4-nitroanilides and barstar Cys40Ala/Cys82Ala/Pro27Ala/Pro48→4-fluoroproline quadruple variants. Generally, PPIase catalysis demonstrated stereospecificity for monofluoro substitutions at the 4-position of the pyrrolidine ring. However, the replacement of hydrogens with fluoro atoms did not impair productive interactions for the majority of PPIase−substrate complexes. Comparison of specificity constants for Oligopeptide and protein substrates revealed striking differences in the 4-fluoroproline substituent effects between members of the ...
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peptidyl prolyl cis trans isomerases comparative reactivities of cyclophilins fk506 binding proteins and parvulins with fluorinated Oligopeptide and protein substrates
Biochemistry, 2005Co-Authors: Ralph Golbik, Elisabeth Weyherstingl, Robert Huber, Luis Moroder, Nediljko Budisa, Cordelia SchienefischerAbstract:Peptidyl prolyl cis/trans-isomerases catalyze the cis-trans isomerization of prolyl bonds in Oligopeptides and various folding states of proteins. The proline residue in PPIase substrates at the P1' subsite, which follows the isomerizing peptide bond, appears to be the common recognition element for all subfamilies of this enzyme class. The molecular principles that govern substrate specificity at the P1' subsite were analyzed using 4-fluoroproline-containing tetrapeptide 4-nitroanilides and barstar Cys40Ala/Cys82Ala/Pro27Ala/Pro48-->4-fluoroproline quadruple variants. Generally, PPIase catalysis demonstrated stereospecificity for monofluoro substitutions at the 4-position of the pyrrolidine ring. However, the replacement of hydrogens with fluoro atoms did not impair productive interactions for the majority of PPIase-substrate complexes. Comparison of specificity constants for Oligopeptide and protein substrates revealed striking differences in the 4-fluoroproline substituent effects between members of the PPIase families. Introduction of 4(R)-fluoroproline resulted in an Oligopeptide substrate completely resistant to catalytic effects of FKBP-like PPIases. By contrast, the 4(R)-fluoroproline barstar variant demonstrated only slightly reduced or even better catalytic susceptibility when compared to the parent barstar Cys40Ala/Cys82Ala/Pro27Ala/Pro48 substrate. On the other hand, Suc-Ala-Ser-4(S)-FPro-Phe-pNA exhibits a discriminating specificity toward the prototypic parvulin, the Escherichia coli Par10. The E. coli trigger factor, in the extreme, catalyzes Cys40Ala/Cys82Ala/Pro27Ala/4-F(2)Pro48 with a more than 20-fold higher efficiency when compared to the proline-containing congener. These findings support the combined subsite concept for PPIase catalysis in which the positioning of a substrate in the active cleft must activate a still unknown number of remote subsites in the transition state of the reaction. The number of critical subsites was shown to vary between the PPIase families.
Edmund R S Kunji - One of the best experts on this subject based on the ideXlab platform.
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the proteolytic systems of lactic acid bacteria
Antonie Van Leeuwenhoek International Journal of General and Molecular Microbiology, 1996Co-Authors: Edmund R S Kunji, Berend Poolman, Igor Mierau, Anja Hagting, Wil N. KoningsAbstract:Proteolysis in dairy lactic acid bacteria has been studied in great detail by genetic, biochemical and ultrastructural methods. From these studies the picture emerges that the proteolytic systems of lactococci and lactobacilli are remarkably similar in their components and mode of action. The proteolytic system consists of an extracellularly located serine-proteinase, transport systems specific for di-tripeptides and Oligopeptides (> 3 residues), and a multitude of intracellular peptidases. This review describes the properties and regulation of individual components as well as studies that have led to identification of their cellular localization. Targeted mutational techniques developed in recent years have made it possible to investigate the role of individual and combinations of enzymes in vivo. Based on these results as well as in vitro studies of the enzymes and transporters, a model for the proteolytic pathway is proposed. The main features are: (i) proteinases have a broad specificity and are capable of releasing a large number of different Oligopeptides, of which a large fraction falls in the range of 4 to 8 amino acid residues; (ii) Oligopeptide transport is the main route for nitrogen entry into the cell; (iii) all peptidases are located intracellularly and concerted action of peptidases is required for complete degradation of accumulated peptides.
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Oligopeptides are the main source of nitrogen for lactococcus lactis during growth in milk
Applied and Environmental Microbiology, 1995Co-Authors: Vincent Juillard, Edmund R S Kunji, Le D Bars, J C Gripon, J RichardAbstract:The consumption of amino acids and peptides was monitored during growth in milk of proteinase-positive (Prt+) and -negative (Prt-) strains of Lactococcus lactis. The Prt- strains showed monophasic exponential growth, while the Prt+ strains grew in two phases. The first growth phases of the Prt+ and Prt- strains were in same, and no hydrolysis of casein was observed. Also, the levels of consumption of amino acids and peptides in the Prt+ and Prt- strains were similar. At the end of this growth phase, not all free amino acids and peptides were used, indicating that the remaining free amino acids and peptides were unable to sustain growth. The consumption of free amino acids was very low (about 5 mg/liter), suggesting that these nitrogen sources play only a minor role in growth. Oligopeptide transport-deficient strains (Opp-) of L. lactis were unable to utilize Oligopeptides and grew poorly in milk. However, a di- and tripeptide transport-deficient strain (DtpT-) grew exactly like the wild type (Opp+ Dtpt+) did. These observations indicate that Oligopeptides represent the main nitrogen source for growth in milk during the first growth phase. In the second phase of growth of Prt+ strains, milk proteins are hydrolyzed to peptides by the proteinase. Several of the Oligopeptides formed are taken up and hydrolyzed internally by peptidases to amino acids, several of which are subsequently released into the medium (see also E.R.S. Kunji, A. Hagting, C.J. De Vries, V. Juillard, A.J. Haandrikman, B. Poolman, and W.N. Konings, J. Biol. Chem. 270:1569-1574, 1995).(ABSTRACT TRUNCATED AT 250 WORDS)
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the extracellular pi type proteinase of lactococcus lactis hydrolyzes beta casein into more than one hundred different Oligopeptides
Journal of Bacteriology, 1995Co-Authors: Vincent Juillard, Edmund R S Kunji, Harry Laan, C M Jeronimusstratingh, A P BruinsAbstract:The peptides released from beta-casein by the action of PI-type proteinase (PrtP) from Lactococcus lactis subsp. cremoris Wg2 have been identified by on-line coupling of liquid chromatography to mass spectrometry. After 24 h of incubation of beta-casein with purified PrtP, a stable mixture of peptides was obtained. The trifluoroacetic acid-soluble peptides of this beta-casein hydrolysate were fractionated by high-performance liquid chromatography and introduced into the liquid chromatography-ion spray mass spectrometry interface. Multiply charged ions were generated from trifluoroacetic acid-soluble peptides under low nozzle voltage conditions, yielding the MH+ mass of each eluted peptide. All peptides corresponding to each of the MH+ calculated masses were determined. In those cases in which different peptides were possible, further identification was achieved by collision-induced dissociation under higher nozzle voltage conditions. Hydrolysis of beta-casein by PrtP was observed to proceed much further than reported previously. More than 40% of the peptide bonds are cleaved by PrtP, resulting in the formation of more than 100 different Oligopeptides. With the exception of Phe, significant release of amino acids or di- and tripeptides could not be observed. Interestingly, one-fifth of the identified Oligopeptides are small enough to be taken up by the Oligopeptide transport system. Uptake of these peptides could supply L. lactis with all amino acids, including the essential ones, indicating that growth of L. lactis might be possible on peptides released from beta-casein by proteinase only.
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di tripeptides and Oligopeptides are taken up via distinct transport mechanisms in lactococcus lactis
Journal of Bacteriology, 1993Co-Authors: Edmund R S Kunji, Ej Smid, Roland Plapp, Berend Poolman, Wil N. KoningsAbstract:Lactococcus lactis ML3 possesses two different peptide transport systems of which the substrate size restriction and specificity have been determined. The first system is the earlier-described proton motive force-dependent di-tripeptide carrier (E. J. Smid, A. J. M. Driessen, and W. N. Konings, J. Bacteriol. 171:292-298, 1989). The second system is a metabolic energy-dependent Oligopeptide transport system which transports peptides of four to at least six amino acid residues. The involvement of a specific Oligopeptide transport system in the utilization of tetra-alanine and penta-alanine was established in a mutant of L. lactis MG1363 that was selected on the basis of resistance to toxic analogs of alanine and alanine-containing di- and tripeptides. This mutant is unable to transport alanine, dialanine, and trialanine but still shows uptake of tetra-alanine and penta-alanine. The Oligopeptide transport system has a lower activity than the di-tripeptide transport system. Uptake of Oligopeptides occurs in the absence of a proton motive force and is specifically inhibited by vanadate. The Oligopeptide transport system is most likely driven by ATP or a related energy-rich, phosphorylated intermediate.
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di tripeptides and Oligopeptides are taken up via distinct transport mechanisms in lactococcus lactis
Journal of Bacteriology, 1993Co-Authors: Edmund R S Kunji, Ej Smid, Roland Plapp, Berend Poolman, Wil N. KoningsAbstract:Lactococcus lactis ML3 possesses two different peptide transport systems of which the substrate size restriction and specificity have been determined. The first system is the earlier-described proton motive force-dependent di-tripeptide carrier (E. J. Smid, A. J. M. Driessen, and W. N. Konings, J. Bacteriol. 171:292-298, 1989). The second system is a metabolic energy-dependent Oligopeptide transport system which transports peptides of four to at least six amino acid residues. The involvement of a specific Oligopeptide transport system in the utilization of tetra-alanine and penta-alanine was established in a mutant of L. lactis MG1363 that was selected on the basis of resistance to toxic analogs of alanine and alanine-containing di- and tripeptides. This mutant is unable to transport alanine, dialanine, and trialanine but still shows uptake of tetra-alanine and penta-alanine. The Oligopeptide transport system has a lower activity than the di-tripeptide transport system. Uptake of Oligopeptides occurs in the absence of a proton motive force and is specifically inhibited by vanadate. The Oligopeptide transport system is most likely driven by ATP or a related energy-rich, phosphorylated intermediate.
Luis Moroder - One of the best experts on this subject based on the ideXlab platform.
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peptidyl prolyl cis trans isomerases comparative reactivities of cyclophilins fk506 binding proteins and parvulins with fluorinated Oligopeptide and protein substrates
Biochemistry, 2005Co-Authors: Ralph Golbik, Elisabeth Weyherstingl, Robert Huber, Luis Moroder, Nediljko Budisa, Cordelia SchienefischerAbstract:Peptidyl prolyl cis/trans-isomerases catalyze the cis−trans isomerization of prolyl bonds in Oligopeptides and various folding states of proteins. The proline residue in PPIase substrates at the P1‘ subsite, which follows the isomerizing peptide bond, appears to be the common recognition element for all subfamilies of this enzyme class. The molecular principles that govern substrate specificity at the P1‘ subsite were analyzed using 4-fluoroproline-containing tetrapeptide 4-nitroanilides and barstar Cys40Ala/Cys82Ala/Pro27Ala/Pro48→4-fluoroproline quadruple variants. Generally, PPIase catalysis demonstrated stereospecificity for monofluoro substitutions at the 4-position of the pyrrolidine ring. However, the replacement of hydrogens with fluoro atoms did not impair productive interactions for the majority of PPIase−substrate complexes. Comparison of specificity constants for Oligopeptide and protein substrates revealed striking differences in the 4-fluoroproline substituent effects between members of the ...
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peptidyl prolyl cis trans isomerases comparative reactivities of cyclophilins fk506 binding proteins and parvulins with fluorinated Oligopeptide and protein substrates
Biochemistry, 2005Co-Authors: Ralph Golbik, Elisabeth Weyherstingl, Robert Huber, Luis Moroder, Nediljko Budisa, Cordelia SchienefischerAbstract:Peptidyl prolyl cis/trans-isomerases catalyze the cis-trans isomerization of prolyl bonds in Oligopeptides and various folding states of proteins. The proline residue in PPIase substrates at the P1' subsite, which follows the isomerizing peptide bond, appears to be the common recognition element for all subfamilies of this enzyme class. The molecular principles that govern substrate specificity at the P1' subsite were analyzed using 4-fluoroproline-containing tetrapeptide 4-nitroanilides and barstar Cys40Ala/Cys82Ala/Pro27Ala/Pro48-->4-fluoroproline quadruple variants. Generally, PPIase catalysis demonstrated stereospecificity for monofluoro substitutions at the 4-position of the pyrrolidine ring. However, the replacement of hydrogens with fluoro atoms did not impair productive interactions for the majority of PPIase-substrate complexes. Comparison of specificity constants for Oligopeptide and protein substrates revealed striking differences in the 4-fluoroproline substituent effects between members of the PPIase families. Introduction of 4(R)-fluoroproline resulted in an Oligopeptide substrate completely resistant to catalytic effects of FKBP-like PPIases. By contrast, the 4(R)-fluoroproline barstar variant demonstrated only slightly reduced or even better catalytic susceptibility when compared to the parent barstar Cys40Ala/Cys82Ala/Pro27Ala/Pro48 substrate. On the other hand, Suc-Ala-Ser-4(S)-FPro-Phe-pNA exhibits a discriminating specificity toward the prototypic parvulin, the Escherichia coli Par10. The E. coli trigger factor, in the extreme, catalyzes Cys40Ala/Cys82Ala/Pro27Ala/4-F(2)Pro48 with a more than 20-fold higher efficiency when compared to the proline-containing congener. These findings support the combined subsite concept for PPIase catalysis in which the positioning of a substrate in the active cleft must activate a still unknown number of remote subsites in the transition state of the reaction. The number of critical subsites was shown to vary between the PPIase families.
