Prepore formation is hypothesized to be an obligate step in the insertion of Cry1Ab toxin into insect brush border membrane vesicles. We examined the architecture of the putative prepore when isolated using the publis...Prepore formation is hypothesized to be an obligate step in the insertion of Cry1Ab toxin into insect brush border membrane vesicles. We examined the architecture of the putative prepore when isolated using the published protocols [1] [2]. Our results demonstrate that the putative prepore form of Cry1Ab is a combination of receptor proteins attached to the toxin, when purified. The results also suggest that this prepore form as prepared by the methods published is different from other membrane-extracted oligomeric forms of Cry toxins and prepore of other toxins in general. While most other known prepores are composed of multimers of a single protein, the Cry1Ab prepore, as generated, is a protein-receptor complex oligomer and monomers of Cry toxins.展开更多
Prebiotics synthesized by probiotic genera are of interest due to their specific selectivity.However,modifications of their composition and concentrations by digestion may affect their properties and effects in the ho...Prebiotics synthesized by probiotic genera are of interest due to their specific selectivity.However,modifications of their composition and concentrations by digestion may affect their properties and effects in the host.In the present study we assessed small intestinal digestibility of oligosaccharides synthesized by Acidipropionibacterium acidipropionici LET120-β-gal(β-galactosidase)from lactose(LET120-GOS),lactulose(LET120-OsLu)and lactitol(LET120-LOS)by incubating them with brush border membrane vesicles(BBMV)from pig and a rat small intestinal extract(RSIE)as in vitro models of mammalian mucosa.Both BBMVs and RSIE partially degraded the potential prebiotic oligosaccharides synthesized by dairy propionibacteria and hydrolysis was influenced by the structure and composition of the oligosaccharides.The highest degradation was observed for LET120-GOS,with 46.8%and 58.1%of hydrolysis after 5 h of digestion with BBMV and RSIE,respectively.On the contrary,LET120-OsLu and LET120-LOS showed higher resistance to intestinal degradation.β(1→6)linked products showed higher resistance to mammalian digestive enzymes compared toβ(1→4)andβ(1→3)linked oligosaccharides.Results emphasize the need of quantifying prebiotics that would reach the colon to anticipate their impact on health and the dose needed to exert that effect.展开更多
文摘Prepore formation is hypothesized to be an obligate step in the insertion of Cry1Ab toxin into insect brush border membrane vesicles. We examined the architecture of the putative prepore when isolated using the published protocols [1] [2]. Our results demonstrate that the putative prepore form of Cry1Ab is a combination of receptor proteins attached to the toxin, when purified. The results also suggest that this prepore form as prepared by the methods published is different from other membrane-extracted oligomeric forms of Cry toxins and prepore of other toxins in general. While most other known prepores are composed of multimers of a single protein, the Cry1Ab prepore, as generated, is a protein-receptor complex oligomer and monomers of Cry toxins.
基金supported by EMHE CSIC 2017,PID2021-123862OBI00 from MICINN,PICT-3504 from ANPCyT(Argentina)Project IC-901 from USPT(Argentina).
文摘Prebiotics synthesized by probiotic genera are of interest due to their specific selectivity.However,modifications of their composition and concentrations by digestion may affect their properties and effects in the host.In the present study we assessed small intestinal digestibility of oligosaccharides synthesized by Acidipropionibacterium acidipropionici LET120-β-gal(β-galactosidase)from lactose(LET120-GOS),lactulose(LET120-OsLu)and lactitol(LET120-LOS)by incubating them with brush border membrane vesicles(BBMV)from pig and a rat small intestinal extract(RSIE)as in vitro models of mammalian mucosa.Both BBMVs and RSIE partially degraded the potential prebiotic oligosaccharides synthesized by dairy propionibacteria and hydrolysis was influenced by the structure and composition of the oligosaccharides.The highest degradation was observed for LET120-GOS,with 46.8%and 58.1%of hydrolysis after 5 h of digestion with BBMV and RSIE,respectively.On the contrary,LET120-OsLu and LET120-LOS showed higher resistance to intestinal degradation.β(1→6)linked products showed higher resistance to mammalian digestive enzymes compared toβ(1→4)andβ(1→3)linked oligosaccharides.Results emphasize the need of quantifying prebiotics that would reach the colon to anticipate their impact on health and the dose needed to exert that effect.
