Synthesis and functionalization of glucan dendrimer, and its application as a drug delivery system carrier

Abstract Glycogen is a natural polysaccharide with a dendrimer structure, in which glucose is frequently branched and polymerized. Functionalizing the numerous non-reducing ends on the molecular surface of glycogen could be expected to enable its use in various fields. We developed a method for enzymatically synthesizing a suitable form of glycogen from sucrose by using sucrose phosphorylase and branching enzyme, both of which belong to the α-amylase family, as well as glucan phosphorylase. We refer to this enzymatically synthesized glycogen as the glucan dendrimer (GD). We then selectively modified the non-reducing ends on the surface of GD particles by using the reaction of glucan phosphorylase with various hexose 1-phosphates. Modifying the non-reducing ends of GD with glucuronic acid or glucosamine added negative and positive charges to the GD particles. In addition, we found that glucuronic acid and/or glucosamine residues at the non-reducing ends can be used to covalently conjugate functional substances, such as sugar chains, proteins, and peptides to the surface of GD particles. GD and modification of its non-reducing ends represent versatile platforms for pharmaceutical applications of polysaccharides.

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α-Glucan Phosphorylase-Catalyzed Enzymatic Reactions Using Analog Substrates to Synthesize Non-Natural Oligo- and Polysaccharides

Catalysts ◽

10.3390/catal8100473 ◽

2018 ◽

Vol 8 (10) ◽

pp. 473 ◽

Cited By ~ 5

Author(s):

Jun-ichi Kadokawa

Keyword(s):

Inorganic Phosphate ◽

Functional Materials ◽

Enzymatic Polymerization ◽

Enzymatic Reactions ◽

Biological Functions ◽

Natural Polysaccharide ◽

Biomass Resources ◽

Practical Synthesis ◽

Glucan Phosphorylase ◽

Glycosyl Donors

As natural oligo- and polysaccharides are important biomass resources and exhibit vital biological functions, non-natural oligo- and polysaccharides with a well-defined structure can be expected to act as new functional materials with specific natures and properties. α-Glucan phosphorylase (GP) is one of the enzymes that have been used as catalysts for practical synthesis of oligo- and polysaccharides. By means of weak specificity for the recognition of substrates by GP, non-natural oligo- and polysaccharides has precisely been synthesized. GP-catalyzed enzymatic glycosylations using several analog substrates as glycosyl donors have been carried out to produce oligosaccharides having different monosaccharide residues at the non-reducing end. Glycogen, a highly branched natural polysaccharide, has been used as the polymeric glycosyl acceptor and primer for the GP-catalyzed glycosylation and polymerization to obtain glycogen-based non-natural polysaccharide materials. Under the conditions of removal of inorganic phosphate, thermostable GP-catalyzed enzymatic polymerization of analog monomers occurred to give amylose analog polysaccharides.

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Platypus venom: source of novel compounds

Australian Journal of Zoology ◽

10.1071/zo09040 ◽

2009 ◽

Vol 57 (4) ◽

pp. 203 ◽

Cited By ~ 12

Author(s):

Jennifer M. S. Koh ◽

Paramjit S. Bansal ◽

Allan M. Torres ◽

Philip W. Kuchel

Keyword(s):

Nerve Growth Factor ◽

Natriuretic Peptides ◽

Venom Gland ◽

Anatomical Feature ◽

Isomerase Activity ◽

Novel Proteins ◽

Pharmaceutical Applications ◽

Ornithorhynchus Anatinus ◽

Animal Venoms ◽

Proteins And Peptides

An anatomical feature of the platypus (Ornithorhynchus anatinus) that is seen in only one other mammal, the echidna, is that the male has a crural glandular system that produces venom that is used for defence and territorial–breeding functions; whether the echidna is similarly venomous is not yet established. Platypus venom contains many novel proteins and peptides that are different from those in reptilian venom. It also causes pain and symptoms that are not experienced by any other kind of envenomation. Five types of proteins and peptides have been isolated and identified from platypus venom, namely: defensin-like peptides (DLPs); Ornithorhynchus venom C-type natriuretic peptides (OvCNPs); Ornithorhynchus nerve growth factor; hyaluronidase; and l-to-d-peptide isomerase. The structures of DLPs and OvCNPs have already been studied and they are very similar to β-defensin-12 and mammalian C-type natriuretic peptides, respectively. A special mammalian l-to-d-peptide isomerase that is responsible for interconverting the l- and d-peptide isomers is also found in platypus venom. Isomerase activity has recently been discovered in platypus tissues other than the venom gland. It is possible that similar kinds of enzymes might exist in other mammals and play important, as yet unknown, biological roles. Considering the fact that some animal venoms have already been widely used in pharmaceutical applications, research into platypus venom may lead to the discovery of new molecules and potent drugs that are useful biomedical tools.

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Subcellular immuno-localization, amino acid composition and partial amino acid sequences of alpha-1,4-glucan phosphorylase of Gracilarria spp (Rhodophyta)

Physiologia Plantarum ◽

10.1034/j.1399-3054.1993.890103.x ◽

1993 ◽

Vol 89 (1) ◽

pp. 11-20

Author(s):

S. Yu ◽

J.-L. Gomez-Pinchetti ◽

B. Ek ◽

G. Garcia-Reina ◽

M. Pedersen

Keyword(s):

Amino Acid ◽

Amino Acid Composition ◽

Acid Composition ◽

Amino Acid Sequences ◽

Glucan Phosphorylase

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Purification of two forms of starch branching enzyme (Q-enzyme) from developing rice endosperm

Physiologia Plantarum ◽

10.1034/j.1399-3054.1992.840302.x ◽

1992 ◽

Vol 84 (3) ◽

pp. 329-335 ◽

Cited By ~ 5

Author(s):

Yasunori Nakamura ◽

Tetsuo Takeichi ◽

Kentaro Kawaguchi ◽

Hiroaki Yamanouchi

Keyword(s):

Branching Enzyme ◽

Starch Branching Enzyme ◽

Rice Endosperm

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Sequencing of Proteins and Peptides

10.1016/s0075-7535(08)x7013-5 ◽

1981 ◽

Keyword(s):

Proteins And Peptides

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CHROMATOGRAPHIC STUDIES ON 131I-COMPOUNDS IN FAECES AND BILE

Acta Endocrinologica ◽

10.1530/acta.0.0470343 ◽

1964 ◽

Vol 47 (2) ◽

pp. 343-352

Author(s):

B. Blomstedt ◽

H. Y. Neujahr

Keyword(s):

Intravenous Administration ◽

Glucuronic Acid ◽

Free Triiodothyronine ◽

Considerable Part ◽

Human Faeces ◽

Total Excretion

ABSTRACT The occurrence of 131I-compounds in human faeces was studied after intravenous administration of 131I-thyroxine. The excretion of the radioactivity during 12 days ranged from 7.8 to 32.1 per cent of the dose administered with a mean of 16.0 (± 1.76). The radioactivity in the faeces was derived from free 131I-thyroxine. The total amount of faeces did not seem to influence the total excretion of the dose administered. After administration of 131I-triiodothyronine to rats and humans, triiodothyronine occurred in the bile mainly conjugated with glucuronic acid, but a considerable part of the radioactivity was found in diiodotyrosine. The radioacivity of human faeces after the administration of 131I-triiodothyronine was derived from free triiodothyronine. After injection of 131I-diiodotyrosine only labelled iodide was detected in the bile of rats. In the bile of humans most of the radioactivity was derived from iodide, and a small part of it was found in diiodotyrosine.

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Angiostatic Proteins and Peptides

Critical Reviews in Eukaryotic Gene Expression ◽

10.1615/critreveukargeneexpr.v11.i4.40 ◽

2001 ◽

Vol 11 (4) ◽

pp. 16 ◽

Cited By ~ 3

Author(s):

Jessica C. A. Bouma-ter Steege ◽

Kevin H. Mayo ◽

Arjan W. Griffioen

Keyword(s):

Proteins And Peptides

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Peripheral CD8 T-Cell Responses to Apoptotic Cell Proteins and Peptides

Critical Reviews™ in Immunology ◽

10.1615/critrevimmunol.v27.i4.50 ◽

2007 ◽

Vol 27 (4) ◽

pp. 357-365 ◽

Cited By ~ 4

Author(s):

Yu Feng Peng ◽

Keith B. Elkon

Keyword(s):

T Cell ◽

Apoptotic Cell ◽

T Cell Responses ◽

Cd8 T Cell ◽

Cell Responses ◽

Proteins And Peptides

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Pharmaceutical Polymers - A Review

International Journal of Drug Delivery Technology ◽

10.25258/ijddt.9.1.5 ◽

2019 ◽

Vol 9 (01) ◽

pp. 27-33

Author(s):

Naveen Kumar ◽

Sonia Pahuja ◽

Ranjit Sharma

Keyword(s):

Drug Release ◽

Industrial Revolution ◽

Pharmaceutical Formulations ◽

Pharmaceutical Products ◽

Water Soluble ◽

Taste Masking ◽

Natural Polymers ◽

Pharmaceutical Dosage Forms ◽

Pharmaceutical Applications ◽

Pharmaceutical Industries

Humans have taken advantage of the adaptability of polymers for centuries in the form of resins, gums tars, and oils. However, it was not until the industrial revolution that the modern polymer industry began to develop. Polymers represent an important constituent of pharmaceutical dosage forms. Polymers have played vital roles in the formulation of pharmaceutical products. Polymers have been used as a major tool to manage the drug release rate from the formulations. Synthetic and natural-based polymers have found their way into the biomedical and pharmaceutical industries. Synthetic and Natural polymers can be produced with a broad range of strength, heat resistance, density, stiffness and even price. By constant research into the science and applications of polymers, they are playing an ever-increasing role in society. Diverse applications of polymers in the present pharmaceutical field are for controlled drug release. Based on solubility pharmaceutical polymers can be classified as water-soluble and water-insoluble. In general, the desirable polymer properties in pharmaceutical applications are film forming, adhesion, gelling, thickening, pH-dependent solubility and taste masking. General pharmaceutical applications of polymers in various pharmaceutical formulations are also discussed

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