Dataset Information

Study of the Potential of the Capsule Shell Based on Natural Polysaccharides in Targeted Delivery of the L-Phenylalanine Ammonia-Lyase Enzyme Preparation.

ABSTRACT: The treatment of classical phenylketonuria is currently represented by many new methods of disease management. A promising method is the use of the enzyme L-phenylalanine ammonia-lyase (PAL) in various forms. The widespread use of enzyme preparations in therapy is limited by a lack of understanding of the mechanisms and systems of the targeted transport of PAL into certain organs and tissues as a result of the incorporation of a drug into the carrier. To ensure the stability of enzymes during the delivery process, encapsulation is preferable, which, as a rule, ensures the preservation of the qualitative characteristics of the enzymes orally applied to the environmental effects of the gastrointestinal tract (acidity, temperature, oxidation, etc.). Capsule preparations showed sufficient stability in the model gastric fluids and sustained release of the drug in the simulated intestinal fluid. Currently, there is a wide range of polymers used for encapsulation. The use of natural sources in the production technology of capsule systems improves bioavailability, controls the release, and prolongs the half-life of active substances. The advantage of this method is that the used enzyme is completely protected by the cell membranes of the capsules, which preserve its stability in the aggressive environment of the gastrointestinal tract. Capsules were obtained on the basis of compositions of hydrocolloids of plant origin. The potential of the developed capsules for targeted delivery of the enzyme preparation was studied. The degradation of the encapsulated form of the PAL enzyme preparation was studied in vitro in model bio-relevant media simulating the gastric and intestinal environment. The dynamics of the breakdown of the capsule shell allow us to expect that the release of L-phenylalanine ammonia-lyase from capsules based on plant hydrocolloids will occur no earlier than reaching the upper intestines, where the interaction with the protein components of the consumed food products to neutralize phenylalanine should occur.

SUBMITTER: Babich O

PROVIDER: S-EPMC7243110 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Study of the Potential of the Capsule Shell Based on Natural Polysaccharides in Targeted Delivery of the L-Phenylalanine Ammonia-Lyase Enzyme Preparation.

Babich Olga O Dyshlyuk Lyubov L Prosekov Alexander A Noskova Svetlana S Ivina Oksana O Pavsky Valery V Ivanova Svetlana S Bulgakova Olga O

Pharmaceuticals (Basel, Switzerland) 20200409 4

The treatment of classical phenylketonuria is currently represented by many new methods of disease management. A promising method is the use of the enzyme L-phenylalanine ammonia-lyase (PAL) in various forms. The widespread use of enzyme preparations in therapy is limited by a lack of understanding of the mechanisms and systems of the targeted transport of PAL into certain organs and tissues as a result of the incorporation of a drug into the carrier. To ensure the stability of enzymes during th ...[more]

PMID: 32283743

Similar Datasets

Project description:BACKGROUND: Phenylalanine ammonia lyase (PAL) is a key enzyme of the phenylpropanoid pathway that catalyzes the deamination of phenylalanine to trans-cinnamic acid, a precursor for the lignin and flavonoid biosynthetic pathways. To date, PAL genes have been less extensively studied in gymnosperms than in angiosperms. Our interest in PAL genes stems from their potential role in the defense responses of Pinus taeda, especially with respect to lignification and production of low molecular weight phenolic compounds under various biotic and abiotic stimuli. In contrast to all angiosperms for which reference genome sequences are available, P. taeda has previously been characterized as having only a single PAL gene. Our objective was to re-evaluate this finding, assess the evolutionary history of PAL genes across major angiosperm and gymnosperm lineages, and characterize PAL gene expression patterns in Pinus taeda. METHODS: We compiled a large set of PAL genes from the largest transcript dataset available for P. taeda and other conifers. The transcript assemblies for P. taeda were validated through sequencing of PCR products amplified using gene-specific primers based on the putative PAL gene assemblies. Verified PAL gene sequences were aligned and a gene tree was estimated. The resulting gene tree was reconciled with a known species tree and the time points for gene duplication events were inferred relative to the divergence of major plant lineages. RESULTS: In contrast to angiosperms, gymnosperms have retained a diverse set of PAL genes distributed among three major clades that arose from gene duplication events predating the divergence of these two seed plant lineages. Whereas multiple PAL genes have been identified in sequenced angiosperm genomes, all characterized angiosperm PAL genes form a single clade in the gene PAL tree, suggesting they are derived from a single gene in an ancestral angiosperm genome. The five distinct PAL genes detected and verified in P. taeda were derived from a combination of duplication events predating and postdating the divergence of angiosperms and gymnosperms. CONCLUSIONS: Gymnosperms have a more phylogenetically diverse set of PAL genes than angiosperms. This inference has contrasting implications for the evolution of PAL gene function in gymnosperms and angiosperms.

Project description:We have recently observed promising success in a mouse model for treating the metabolic disorder phenylketonuria with phenylalanine ammonia lyase (PAL) from Rhodosporidium toruloides and Anabaena variabilis. Both molecules, however, required further optimization in order to overcome problems with protease susceptibility, thermal stability, and aggregation. Previously, we optimized PAL from R. toruloides, and in this case we reduced aggregation of the A. variabilis PAL by mutating two surface cysteine residues (C503 and C565) to serines. Additionally, we report the structural and biochemical characterization of the A. variabilis PAL C503S/C565S double mutant and carefully compare this molecule with the R. toruloides engineered PAL molecule. Unlike previously published PAL structures, significant electron density is observed for the two active-site loops in the A. variabilis C503S/C565S double mutant, yielding a complete view of the active site. Docking studies and N-hydroxysuccinimide-biotin binding studies support a proposed mechanism in which the amino group of the phenylalanine substrate is attacked directly by the 4-methylidene-imidazole-5-one prosthetic group. We propose a helix-to-loop conformational switch in the helices flanking the inner active-site loop that regulates accessibility of the active site. Differences in loop stability among PAL homologs may explain the observed variation in enzyme efficiency, despite the highly conserved structure of the active site. A. variabilis C503S/C565S PAL is shown to be both more thermally stable and more resistant to proteolytic cleavage than R. toruloides PAL. Additional increases in thermal stability and protease resistance upon ligand binding may be due to enhanced interactions among the residues of the active site, possibly locking the active-site structure in place and stabilizing the tetramer. Examination of the A. variabilis C503S/C565S PAL structure, combined with analysis of its physical properties, provides a structural basis for further engineering of residues that could result in a better therapeutic molecule.

Dataset Information

Study of the Potential of the Capsule Shell Based on Natural Polysaccharides in Targeted Delivery of the L-Phenylalanine Ammonia-Lyase Enzyme Preparation.

Publications

Study of the Potential of the Capsule Shell Based on Natural Polysaccharides in Targeted Delivery of the L-Phenylalanine Ammonia-Lyase Enzyme Preparation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets