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Clélia Ferreira - One of the best experts on this subject based on the ideXlab platform.
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Peritrophic Membrane role in enhancing digestive efficiency theoretical and experimental models
Journal of Insect Physiology, 2008Co-Authors: Renata Bolognesi, Walter R. Terra, Clélia FerreiraAbstract:The Peritrophic Membrane (PM) is an anatomical structure surrounding the food bolus in most insects. Rejecting the idea that PM has evolved from coating mucus to play the same protective role as it, novel functions were proposed and experimentally tested. The theoretical principles underlying the digestive enzyme recycling mechanism were described and used to develop an algorithm to calculate enzyme distributions along the midgut and to infer secretory and absorptive sites. The activity of a Spodoptera frugiperda microvillar aminopeptidase decreases by 50% if placed in the presence of midgut contents. S. frugiperda trypsin preparations placed into dialysis bags in stirred and unstirred media have activities of 210 and 160%, respectively, over the activities of samples in a test tube. The ectoPeritrophic fluid (EF) present in the midgut caeca of Rhynchosciara americana may be collected. If the enzymes restricted to this fluid are assayed in the presence of PM contents (PMC) their activities decrease by at least 58%. The lack of PM caused by calcofluor feeding impairs growth due to an increase in the metabolic cost associated with the conversion of food into body mass. This probably results from an increase in digestive enzyme excretion and useless homeostatic attempt to reestablish destroyed midgut gradients. The experimental models support the view that PM enhances digestive efficiency by: (a) prevention of non-specific binding of undigested material onto cell surface; (b) prevention of excretion by allowing enzyme recycling powered by an ectoPeritrophic counterflux of fluid; (c) removal from inside PM of the oligomeric molecules that may inhibit the enzymes involved in initial digestion; (d) restriction of oligomer hydrolases to ectoPeritrophic space (ECS) to avoid probable partial inhibition by non-dispersed undigested food. Finally, PM functions are discussed regarding insects feeding on any diet.
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structure processing and midgut secretion of putative Peritrophic Membrane ancillary protein pmap from tenebrio molitor larvae
Insect Biochemistry and Molecular Biology, 2008Co-Authors: Alexandre Ferreira, Walter R. Terra, Plinio T Cristofoletti, Daniel C Pimenta, Alberto F Ribeiro, Clélia FerreiraAbstract:A cDNA coding for a Tenebrio molitor midgut protein named Peritrophic Membrane ancillary protein (PMAP) was cloned and sequenced. The complete cDNA codes for a protein of 595 amino acids with six insect-allergen-related-repeats that may be grouped in A (predicted globular)- and B (predicted nonglobular)-types forming an ABABAB structure. The PMAP–cDNA was expressed in Pichia pastoris and the recombinant protein (64 kDa) was purified to homogeneity and used to raise antibodies in rabbits. The specific antibody detected PMAP peptides (22 kDa) in the anterior and middle midgut tissue, luminal contents, Peritrophic Membrane and feces. These peptides derive from PMAP, as supported by mass spectrometry, and resemble those formed by the in vitro action of trypsin on recombinant PMAP. Both in vitro and in vivo PMAP processing seem to occur by attack of trypsin to susceptible bonds in the coils predicted to link AB pairs, thus releasing the putative functional AB structures. The AB-domain structure of PMAP is found in homologous proteins from several insect orders, except lepidopterans that have the apparently derived protein known as nitrile-specifier protein. Immunocytolocalization shows that PMAP is secreted by exocytosis and becomes entrapped in the glycocalyx, before being released into midgut contents. Circumstantial evidence suggests that PMAP-like proteins have a role in Peritrophic Membrane type 2 formation.
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the Peritrophic Membrane of spodoptera frugiperda secretion of peritrophins and role in immobilization and recycling digestive enzymes
Archives of Insect Biochemistry and Physiology, 2001Co-Authors: Renata Bolognesi, Alberto F Ribeiro, Walter R. Terra, Clélia FerreiraAbstract:A peritrophin from the Spodoptera frugiperda Peritrophic Membrane (PM) and microvillar proteins from S. frugiperda anterior midgut cells were isolated and used to raise antibodies in a rabbit. These antibodies, as well as a Tenebrio molitor amylase antibody that cross-reacts with S. frugiperda amylases, and wheat-germ aglutinin were used in immunolocalization experiments performed with the aid of confocal fluorescence and immunogold techniques. The results showed that the peritrophin was secreted by anterior midgut columnar cells in vesicles pinched-off the microvilli (microapocrine secretion). The resulting double Membrane vesicles become single Membrane vesicles by Membrane fusion, releasing peritrophin and part of the amylase and trypsin. The remaining Membranes still containing microvillar proteins and Membrane-bound amylase and trypsin are incorporated into a jelly-like material associated with PM. Calcofluor-treated larvae lacking a PM were shown to lose the decreasing gradient of trypsin and chymotrypsin observed along the midgut of control larvae. This gradient is thought to be formed by a countercurrent flux of fluid (in the space between PM and midgut cells) that powers enzyme recycling.
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Properties of the digestive enzymes and the permeability of the Peritrophic Membrane of Spodoptera frugiperda (Lepidoptera) larvae
Comparative Biochemistry and Physiology Part A: Physiology, 1994Co-Authors: Clélia Ferreira, Adriana N. Capella, Roberta Sitnik, Walter R. TerraAbstract:Abstract The physical and kinetic properties of several soluble and detergent-solubilized Membrane-bound midgut hydrolases of Spodoptera frugiperda (Lepidoptera) were investigated. The following techniques were employed: isoelectric focusing and electrophoresis in polyacrylamide gels, density-gradient ultracentrifugation and gel filtration in Superose columns. In vivo molecular weights of the hydrolases were considered to correspond with those determined by centrifugation, which is the more gentle of the procedures employed. Using this criterion, the soluble hydrolases display the following number of sub-units: acetylglucosaminidase [pHo5 (pH optimum), Mr 123,000], 2; aminopeptidase (pHo 7.4, Mr 107,000), 2; amylase (pHo9.6, Km for starch 0.38%, Mr 87,000), 1; carboxypeptidase A (pHo 8.0, Mr 45,000), 2; cellobiase (pHo 7.0, Mr 124,000), 2; dipeptidase (pHo 8.0, Mr 95,000), 2; maltase (pHo 5.0, Mr 150,000), 2; trypsin (pHo 7.9, Mr 51,000), 2. Amylase is not activated by chloride. A comparison between the diameters of the enzymes which pass through the Peritrophic Membrane (amylase, carboxypeptidase and trypsin) with that which is secreted into the lumen but do not pass through the Peritrophic Membrane (acetylglucosaminase) suggests that the pores of S. frugiperda larval Peritrophic Membrane have diameters of 7.5–8 nm.
Walter R. Terra - One of the best experts on this subject based on the ideXlab platform.
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Peritrophic Membrane role in enhancing digestive efficiency theoretical and experimental models
Journal of Insect Physiology, 2008Co-Authors: Renata Bolognesi, Walter R. Terra, Clélia FerreiraAbstract:The Peritrophic Membrane (PM) is an anatomical structure surrounding the food bolus in most insects. Rejecting the idea that PM has evolved from coating mucus to play the same protective role as it, novel functions were proposed and experimentally tested. The theoretical principles underlying the digestive enzyme recycling mechanism were described and used to develop an algorithm to calculate enzyme distributions along the midgut and to infer secretory and absorptive sites. The activity of a Spodoptera frugiperda microvillar aminopeptidase decreases by 50% if placed in the presence of midgut contents. S. frugiperda trypsin preparations placed into dialysis bags in stirred and unstirred media have activities of 210 and 160%, respectively, over the activities of samples in a test tube. The ectoPeritrophic fluid (EF) present in the midgut caeca of Rhynchosciara americana may be collected. If the enzymes restricted to this fluid are assayed in the presence of PM contents (PMC) their activities decrease by at least 58%. The lack of PM caused by calcofluor feeding impairs growth due to an increase in the metabolic cost associated with the conversion of food into body mass. This probably results from an increase in digestive enzyme excretion and useless homeostatic attempt to reestablish destroyed midgut gradients. The experimental models support the view that PM enhances digestive efficiency by: (a) prevention of non-specific binding of undigested material onto cell surface; (b) prevention of excretion by allowing enzyme recycling powered by an ectoPeritrophic counterflux of fluid; (c) removal from inside PM of the oligomeric molecules that may inhibit the enzymes involved in initial digestion; (d) restriction of oligomer hydrolases to ectoPeritrophic space (ECS) to avoid probable partial inhibition by non-dispersed undigested food. Finally, PM functions are discussed regarding insects feeding on any diet.
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structure processing and midgut secretion of putative Peritrophic Membrane ancillary protein pmap from tenebrio molitor larvae
Insect Biochemistry and Molecular Biology, 2008Co-Authors: Alexandre Ferreira, Walter R. Terra, Plinio T Cristofoletti, Daniel C Pimenta, Alberto F Ribeiro, Clélia FerreiraAbstract:A cDNA coding for a Tenebrio molitor midgut protein named Peritrophic Membrane ancillary protein (PMAP) was cloned and sequenced. The complete cDNA codes for a protein of 595 amino acids with six insect-allergen-related-repeats that may be grouped in A (predicted globular)- and B (predicted nonglobular)-types forming an ABABAB structure. The PMAP–cDNA was expressed in Pichia pastoris and the recombinant protein (64 kDa) was purified to homogeneity and used to raise antibodies in rabbits. The specific antibody detected PMAP peptides (22 kDa) in the anterior and middle midgut tissue, luminal contents, Peritrophic Membrane and feces. These peptides derive from PMAP, as supported by mass spectrometry, and resemble those formed by the in vitro action of trypsin on recombinant PMAP. Both in vitro and in vivo PMAP processing seem to occur by attack of trypsin to susceptible bonds in the coils predicted to link AB pairs, thus releasing the putative functional AB structures. The AB-domain structure of PMAP is found in homologous proteins from several insect orders, except lepidopterans that have the apparently derived protein known as nitrile-specifier protein. Immunocytolocalization shows that PMAP is secreted by exocytosis and becomes entrapped in the glycocalyx, before being released into midgut contents. Circumstantial evidence suggests that PMAP-like proteins have a role in Peritrophic Membrane type 2 formation.
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the Peritrophic Membrane of spodoptera frugiperda secretion of peritrophins and role in immobilization and recycling digestive enzymes
Archives of Insect Biochemistry and Physiology, 2001Co-Authors: Renata Bolognesi, Alberto F Ribeiro, Walter R. Terra, Clélia FerreiraAbstract:A peritrophin from the Spodoptera frugiperda Peritrophic Membrane (PM) and microvillar proteins from S. frugiperda anterior midgut cells were isolated and used to raise antibodies in a rabbit. These antibodies, as well as a Tenebrio molitor amylase antibody that cross-reacts with S. frugiperda amylases, and wheat-germ aglutinin were used in immunolocalization experiments performed with the aid of confocal fluorescence and immunogold techniques. The results showed that the peritrophin was secreted by anterior midgut columnar cells in vesicles pinched-off the microvilli (microapocrine secretion). The resulting double Membrane vesicles become single Membrane vesicles by Membrane fusion, releasing peritrophin and part of the amylase and trypsin. The remaining Membranes still containing microvillar proteins and Membrane-bound amylase and trypsin are incorporated into a jelly-like material associated with PM. Calcofluor-treated larvae lacking a PM were shown to lose the decreasing gradient of trypsin and chymotrypsin observed along the midgut of control larvae. This gradient is thought to be formed by a countercurrent flux of fluid (in the space between PM and midgut cells) that powers enzyme recycling.
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The origin and functions of the insect Peritrophic Membrane and Peritrophic gel.
Archives of insect biochemistry and physiology, 2001Co-Authors: Walter R. TerraAbstract:There is a a fluid (Peritrophic gel) or membranous (Peritrophic Membrane, PM) film surrounding the food bolus in most insects. The PM is composed of chitin and proteins, of which peritrophins are the most important. It is proposed here that, during evolution, midgut cells initially synthesized chitin and peritrophins derived from mucins by acquiring chitin-binding domains, thus permitting the formation of PM. Since PM compartmentalizes the midgut, new physiological roles were added to those of the ancestral mucus (protection against abrasion and microorganism invasion). These new roles are reviewed in the light of data on PM permeability and on enzyme compartmentalization, fluid fluxes, and ultrastructure of the midgut. The importance of the new roles in relation to those of protection is evaluated from data obtained with insects having disrupted PM. Finally, there is growing evidence suggesting that a Peritrophic gel occurs when a highly permeable Peritrophic structure is necessary or when chitin-binding molecules or chitinase are present in food.
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Properties of the digestive enzymes and the permeability of the Peritrophic Membrane of Spodoptera frugiperda (Lepidoptera) larvae
Comparative Biochemistry and Physiology Part A: Physiology, 1994Co-Authors: Clélia Ferreira, Adriana N. Capella, Roberta Sitnik, Walter R. TerraAbstract:Abstract The physical and kinetic properties of several soluble and detergent-solubilized Membrane-bound midgut hydrolases of Spodoptera frugiperda (Lepidoptera) were investigated. The following techniques were employed: isoelectric focusing and electrophoresis in polyacrylamide gels, density-gradient ultracentrifugation and gel filtration in Superose columns. In vivo molecular weights of the hydrolases were considered to correspond with those determined by centrifugation, which is the more gentle of the procedures employed. Using this criterion, the soluble hydrolases display the following number of sub-units: acetylglucosaminidase [pHo5 (pH optimum), Mr 123,000], 2; aminopeptidase (pHo 7.4, Mr 107,000), 2; amylase (pHo9.6, Km for starch 0.38%, Mr 87,000), 1; carboxypeptidase A (pHo 8.0, Mr 45,000), 2; cellobiase (pHo 7.0, Mr 124,000), 2; dipeptidase (pHo 8.0, Mr 95,000), 2; maltase (pHo 5.0, Mr 150,000), 2; trypsin (pHo 7.9, Mr 51,000), 2. Amylase is not activated by chloride. A comparison between the diameters of the enzymes which pass through the Peritrophic Membrane (amylase, carboxypeptidase and trypsin) with that which is secreted into the lumen but do not pass through the Peritrophic Membrane (acetylglucosaminase) suggests that the pores of S. frugiperda larval Peritrophic Membrane have diameters of 7.5–8 nm.
Ping Wang - One of the best experts on this subject based on the ideXlab platform.
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functional redundancy of structural proteins of the Peritrophic Membrane in trichoplusia ni
Insect Biochemistry and Molecular Biology, 2020Co-Authors: Shaohua Wang, Ping WangAbstract:Abstract The Peritrophic Membrane (or Peritrophic matrix) (PM) in insects is formed by binding of PM proteins with multiple chitin binding domains (CBDs) to chitin fibrils. Multi-CBD chitin binding proteins (CBPs) and the insect intestinal mucin (IIM) are major PM structural proteins. To understand the biochemical and physiological role of IIM in structural formation and physiological function of the PM, Trichoplusia ni mutant strains lacking IIM were generated by CRISPR/Cas9 mutagenesis. The mutant T. ni larvae were confirmed to lack IIM, but PM formation was observed as in wild type larvae and lacking IIM in the PM did not result in changes of protease activities in the larval midgut. Larval growth and development of the mutant strains were similar to the wild type strain on artificial diet and cabbage leaves, but had a decreased survival in the 5th instar. The larvae of the mutant strains with the PM formed without IIM did not have a change of susceptibility to the infection of the baculovirus AcMNPV and the Bacillus thuringiensis (Bt) formulation Dipel, to the toxicity of the Bt toxins Cry1Ac and Cry2Ab and the chemical insecticide sodium aluminofluoride. Treatment of the mutant T. ni larvae with Calcofluor reduced the larval susceptibility to the toxicity of Bt Cry1Ac, as similarly observed in the wild type larvae. Overall, in the mutant T. ni larvae, the PM was formed without IIM and the lacking of IIM in the PM did not drastically impact the performance of larvae on diet or cabbage leaves under the laboratory conditions.
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interaction of trichoplusia ni granulosis virus encoded enhancin with the midgut epithelium and Peritrophic Membrane of four lepidopteran insects
Journal of General Virology, 1994Co-Authors: Ping Wang, Daniel A Hammer, Robert R GranadosAbstract:Enhancin, an infectivity-enhancing protein from Trichoplusia ni granulosis virus (TnGV) was tested for its ability to increase Autographa californica multiple nucleocapsid nuclear polyhedrosis virus (AcMNPV) infection in the larvae of four lepidopteran insects. Enhancin increased the mortality of AcMNPV infection in all the four insect species tested. Peritrophic Membrane (PM) assays showed altered protein profiles in PMs treated with enhancin in all the four species. This supports the hypothesis that enhancin affects virus infection by altering the structural integrity of the PMs. The binding of enhancin to the midgut brush border Membranes (BBMs) was determined and specific binding sites were found on the BBM of Pseudaletia unipuncta. No specific binding sites were found on the BBMs of T. ni, Helicoverpa zea or Spodoptera exigua. Therefore, specific binding of enhancin to the midgut cell Membrane may not be necessary for the enhancement of baculovirus infection in insects.
Zhonghuai Xiang - One of the best experts on this subject based on the ideXlab platform.
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Identification and molecular characterization of a chitin deacetylase from Bombyx mori Peritrophic Membrane.
International Journal of Molecular Sciences, 2014Co-Authors: Xiao-wu Zhong, Xiaohuan Wang, Xiang Tan, Qingyou Xia, Zhonghuai Xiang, Ping ZhaoAbstract:The insect midgut epithelium is generally lined with a unique chitin and protein structure, the Peritrophic Membrane (PM), which facilitates food digestion and protects the gut epithelium. PM proteins are important determinants for PM structure and formation. In this study, the silkworm Bombyx mori midgut PM protein BmCDA7 was identified by proteomic tools. The full-length BmCDA7 cDNA is 1357 bp; the deduced protein is composed of 379 amino acid residues and includes a 16 amino acid residue signal peptide, a putative polysaccharide deacetylase-like domain and 15 cysteine residues present in three clusters. The heterologously expressed proteins of the BmCDA7 gene in yeast displayed chitin deacetylase activity. Expression of B. mori BmCDA7 was detected in the midgut at both the transcriptional and translational levels. The BmCDA7 gene was expressed by the newly hatched silkworm larvae until day seven of the fifth instar and was expressed at a high level in the newly exuviated larvae of different instars. The functions and regulatory mechanism of BmCDA7, however, need further investigation.
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Shotgun analysis on the Peritrophic Membrane of the silkworm Bombyx mori.
BMB reports, 2012Co-Authors: Xiao-wu Zhong, Ping Zhao, Liping Zhang, Yong Zou, Xia Qingyou, Zhonghuai XiangAbstract:The insect midgut epithelium is generally lined with a unique chitin and protein structure, the Peritrophic Membrane (PM), which facilitates food digestion and protects the gut epithelium. We used gel electrophoresis and mass spectrometry to identify the extracted proteins from the silkworm PM to obtain an in-depth understanding of the biological function of the silkworm PM components. A total of 305 proteins, with molecular weights ranging from 8.02 kDa to 788.52 kDa and the isoelectric points ranging from 3.39 to 12.91, were successfully identified. We also found several major classes of PM proteins, i.e. PM chitin-binding protein, invertebrate intestinal mucin, and chitin deacetylase. The protein profile provides a basis for further study of the physiological events in the PM of Bombyx mori.
Elisa Aparecida Gregório - One of the best experts on this subject based on the ideXlab platform.
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susceptibility resistance of anticarsia gemmatalis larvae to its nucleopolyhedrovirus agmnpv structural study of the Peritrophic Membrane
Journal of Invertebrate Pathology, 2007Co-Authors: Sheila Michele Levy, Flavio Moscardi, ângela Maria Ferreira Falleiros, Elisa Aparecida GregórioAbstract:This investigation compares the Peritrophic Membrane (PM) morphology along the midgut of susceptible (SL) and resistant (RL) Anticarsia gemmatalis larvae to the AgMNPV. The PM increased the thickness from the anterior to the posterior midgut region in both insects strain; however, the intensity of FITC-WGA reaction of the PM in the RL were greater than in SL. The PM in RL was ultrastructurally constituted by several layers of fibrous/vesicular materials in comparison with the few ones in SL. Our results showed that the structure of PM in the RL could be one of the resistance barriers to AgMNPV.
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Susceptibility/resistance of Anticarsia gemmatalis larvae to its nucleopolyhedrovirus (AgMNPV): Structural study of the Peritrophic Membrane
Journal of Invertebrate Pathology, 2007Co-Authors: Sheila Michele Levy, Flavio Moscardi, ângela Maria Ferreira Falleiros, Elisa Aparecida GregórioAbstract:This investigation compares the Peritrophic Membrane (PM) morphology along the midgut of susceptible (SL) and resistant (RL) Anticarsia gemmatalis larvae to the AgMNPV. The PM increased the thickness from the anterior to the posterior midgut region in both insects strain; however, the intensity of FITC-WGA reaction of the PM in the RL were greater than in SL. The PM in RL was ultrastructurally constituted by several layers of fibrous/vesicular materials in comparison with the few ones in SL. Our results showed that the structure of PM in the RL could be one of the resistance barriers to AgMNPV.
