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Liu X, Gilbert RG. Normal and abnormal glycogen structure - A review. Carbohydr Polym 2024; 338:122195. [PMID: 38763710 DOI: 10.1016/j.carbpol.2024.122195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 04/18/2024] [Accepted: 04/20/2024] [Indexed: 05/21/2024]
Abstract
Glycogen, a complex branched glucose polymer, is found in animals and bacteria, where it serves as an energy storage molecule. It has linear (1 → 4)-α glycosidic bonds between anhydroglucose monomer units, with branch points connected by (1 → 6)-α bonds. Individual glycogen molecules are referred to as β particles. In organs like the liver and heart, these β particles can bind into larger aggregate α particles, which exhibit a rosette-like morphology. The mechanisms and bonding underlying the aggregation process are not fully understood. For example, mammalian liver glycogen has been observed to be molecularly fragile under certain conditions, such as glycogen from diabetic livers fragmenting when exposed to dimethyl sulfoxide (DMSO), while glycogen from healthy livers is much less fragile; this indicates some difference, as yet unknown, in the bonding between β particles in healthy and diabetic glycogen. This fragility may have implications for blood sugar regulation, especially in pathological conditions such as diabetes.
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Affiliation(s)
- Xin Liu
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Zhongshan Biological Breeding Laboratory, and Jiangsu Key Laboratory of Crop Genetics and Physiology, College of Agriculture, Yangzhou University, Yangzhou 225009, China; Centre for Nutrition & Food Sciences, Queensland Alliance for Agriculture & Food Innovations (QAAFI), The University of Queensland, QLD 4072, Australia
| | - Robert G Gilbert
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Zhongshan Biological Breeding Laboratory, and Jiangsu Key Laboratory of Crop Genetics and Physiology, College of Agriculture, Yangzhou University, Yangzhou 225009, China; Centre for Nutrition & Food Sciences, Queensland Alliance for Agriculture & Food Innovations (QAAFI), The University of Queensland, QLD 4072, Australia.
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Kajiura H, Takata H, Akiyama T, Ueyama R, Kakutani R, Furuyashiki T, Kojima I, Takeda R, Kuriki T. A New Method for in vitro Glycogen Synthesis, and the Structure and Properties of the Synthesized Glycogen. J Appl Glycosci (1999) 2010. [DOI: 10.5458/jag.57.105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Hernández JM, Gaborieau M, Castignolles P, Gidley MJ, Myers AM, Gilbert RG. Mechanistic Investigation of a Starch-Branching Enzyme Using Hydrodynamic Volume SEC Analysis. Biomacromolecules 2008; 9:954-65. [DOI: 10.1021/bm701213p] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Javier M. Hernández
- Centre for Nutrition & Food Sciences, School of Land Crop & Food Sciences, University of Queensland, Brisbane, Queensland 4072, Australia, Key Centre for Polymer Colloids, School of Chemistry, University of Sydney, NSW 2006, Australia, Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011
| | - Marianne Gaborieau
- Centre for Nutrition & Food Sciences, School of Land Crop & Food Sciences, University of Queensland, Brisbane, Queensland 4072, Australia, Key Centre for Polymer Colloids, School of Chemistry, University of Sydney, NSW 2006, Australia, Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011
| | - Patrice Castignolles
- Centre for Nutrition & Food Sciences, School of Land Crop & Food Sciences, University of Queensland, Brisbane, Queensland 4072, Australia, Key Centre for Polymer Colloids, School of Chemistry, University of Sydney, NSW 2006, Australia, Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011
| | - Michael J. Gidley
- Centre for Nutrition & Food Sciences, School of Land Crop & Food Sciences, University of Queensland, Brisbane, Queensland 4072, Australia, Key Centre for Polymer Colloids, School of Chemistry, University of Sydney, NSW 2006, Australia, Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011
| | - Alan M. Myers
- Centre for Nutrition & Food Sciences, School of Land Crop & Food Sciences, University of Queensland, Brisbane, Queensland 4072, Australia, Key Centre for Polymer Colloids, School of Chemistry, University of Sydney, NSW 2006, Australia, Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011
| | - Robert G. Gilbert
- Centre for Nutrition & Food Sciences, School of Land Crop & Food Sciences, University of Queensland, Brisbane, Queensland 4072, Australia, Key Centre for Polymer Colloids, School of Chemistry, University of Sydney, NSW 2006, Australia, Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011
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12
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Takata H, Takaha T, Okada S, Hizukuri S, Takagi M, Imanaka T. Structure of the cyclic glucan produced from amylopectin by Bacillus stearothermophilus branching enzyme. Carbohydr Res 1996; 295:91-101. [PMID: 9002186 DOI: 10.1016/s0008-6215(96)90126-3] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The thermostable branching enzyme (BE, EC 2.4.1.18) from Bacillus stearothermophilus TRBE14 produces large cyclic glucans from waxy rice amylopectin similar to those obtained from amylose as described elsewhere [H. Takata, T. Takaha, S. Okada. M. Takagi, and T. Imanaka, J. Bacteriol., 178 (1996) 1600-1606]. The structure of the product (P-1) from the late-stage reaction was analyzed in detail. The weight-average degree of polymerization (dpw) of P-1 was 900. Its chain-length distribution was not significantly changed compared with that of amylopectin, although the amount of long chains (dp > 38) was slightly decreased. The cyclic component of P-1, which was isolated by the extensive action of glucoamylase, had dpw of 49. Three point five alpha-1,6 linkages were directly involved in the formation of the ring structure with several non-cyclic side chains linked to the ring. Based on these results, the action and new roles of BE are discussed.
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Affiliation(s)
- H Takata
- Biochemical Research Laboratory, Ezaki Glico Co., Ltd., Osaka, Japan
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13
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Takata H, Takaha T, Okada S, Takagi M, Imanaka T. Cyclization reaction catalyzed by branching enzyme. J Bacteriol 1996; 178:1600-6. [PMID: 8626287 PMCID: PMC177844 DOI: 10.1128/jb.178.6.1600-1606.1996] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The action of branching enzyme (EC 2.4.l.l8) from Bacillus stearothermophilus on amylose was analyzed. The enzyme reduced the molecular size of amylose without increasing the reducing power. This result could not be explained by the normal branching reaction model. When the product was treated with glucoamylase (an exo++-type amylase), a resistant component remained. The glucoamylase-resistant component was easily digested by an endo-type alpha-amylase or by isoamylase plus glucoamylase. These results suggested that the glucoamylase-resistant component was a cyclic glucan composed of alpha-1,4- and alpha-l,6-glucosidic linkages. In other words, it was suggested that branching enzyme catalyzed cyclization of the alpha-l,4-glucan chain of the amylose molecule to form an alpha-l,6-glucosidic linkage, thereby forming two smaller molecules. Mass spectrometry also supported the cyclic nature of the product.
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Affiliation(s)
- H Takata
- Biochemical Research Laboratory, Ezaki Glico Co., Ltd., Nishiyodogawa-ku, Osaka, Japan
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14
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Tolmasky DS, Krisman CR. The degree of branching in (alpha 1,4)-(alpha 1,6)-linked glucopolysaccharides is dependent on intrinsic properties of the branching enzymes. EUROPEAN JOURNAL OF BIOCHEMISTRY 1987; 168:393-7. [PMID: 2959476 DOI: 10.1111/j.1432-1033.1987.tb13432.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
1. Branching enzymes from rat and rabbit liver, as well as from potato and maize were prepared. They were almost free from contaminating glucan-degrading enzymes. 2. In 'sweet corn' maize, two separate fractions with (alpha 1,4)glucan: (alpha 1,4)glucan alpha 6-glycosyltransferase activities were obtained. One of them synthesized amylopectin, the branched component of starch, in the presence of phosphorylase and Glc1P, while the other fraction synthesized phytoglycogen. Furthermore, in a maize variety which does not accumulate phytoglycogen, only one fraction of branching activity was found, that formed amylopectin under the above-mentioned conditions. 3. Comparative analyses performed with native (alpha 1,4)-(alpha 1,6)glucopolysaccharides, and those synthesized in vitro with the branching enzyme from the same tissue, demonstrated a close similarity between both glucans. 4. It may be concluded that the branching enzyme is responsible for the specific degree of (alpha 1,6) branch linkages found in the native polysaccharide.
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Affiliation(s)
- D S Tolmasky
- Instituo de Investigaciones Bioquimicas Fundacion Campomar, Facultad de Ciencias Exactas y Naturales, Buenos Aires, Argentina
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Hedman KD, Boyer CD. Gene dosage at the amylose-extender locus of maize: effects on the levels of starch branching enzymes. Biochem Genet 1982; 20:483-92. [PMID: 6214251 DOI: 10.1007/bf00484699] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Soluble starch branching enzymes and starch synthases from maize kernels of differing dosage of the ae locus were purified by DEAE-cellulose chromatography. A near-linear relationship between increasing dosage of the dominate amylose-extender allele (Ae) and branching enzyme IIb activity was found. In contrast, levels and properties of branching enzymes I and IIa, as well as the citrate-stimulated and primer-requiring starch synthases, remained unchanged. The near-linear increase in branching enzyme IIb activity with increasing doses of the Ae allele is consistent with the hypothesis that ae is the structural gene coding for branching enzyme IIb.
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