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Rodriguez IR, Taravel FR, Whelan WJ. Identification of the Enzymes Responsible for the Conversion of Starch into Glucose in the Mammalian Digestive Tract. Crit Rev Biotechnol 2008. [DOI: 10.3109/07388558709086982] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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3
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Ryman BE, Whelan WJ. New aspects of glycogen metabolism. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 34:285-443. [PMID: 4335607 DOI: 10.1002/9780470122792.ch6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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4
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Mercier C, Kainuma K. Enzymatic Debranching of Starches from Maize of Various Genotypes in High Concentration of Dimethylsulphoxide. STARCH-STARKE 2006. [DOI: 10.1002/star.19750270902] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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5
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Peuler JD, Lee JM, Smith JM. 4-Aminopyridine antagonizes the acute relaxant action of metformin on adrenergic contraction in the ventral tail artery of the rat. Life Sci 1999; 65:PL 287-93. [PMID: 10622240 DOI: 10.1016/s0024-3205(99)00522-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The ability of metformin (MF) to acutely relax phenylephrine (PE)-induced contraction in the isolated rat tail artery is reported to be accompanied by repolarization of the arterial smooth muscle cell (SMC) membranes. These membranes contain potassium (K) channels which if opened could mediate such repolarization and resultant relaxation. We have shown that the acute relaxation of rat tail arterial tissue rings by graded levels of MF > or = 0.24 mmol/L is markedly antagonized by a high concentration of tetraethylammonium (TEA; 10 mmol/L) which nonselectively inhibits nearly all K channels. Thus, we tested effects of more selective inhibitors of K channels in the same tissue. We also tested MF for relaxation of contractions induced by high levels of extracellular K. To avoid confounding variables, we also conducted these tests in arterial rings in which endothelium and sympathetic nerve endings had been removed. In the absence of K channel inhibition, half-maximal PE-induced contractions were rapidly relaxed by all levels of MF with an EC50 of 1.7+/-0.2 mmol/L (n=8 rings). 1 mmol/L 4-aminopyridine (4AP) which only inhibits voltage-operated and ATP-sensitive K channels markedly antagonized this relaxation, shifting the EC50 for MF to 7.5+/-0.7 mmol/L (n=8; p < 0.05). TEA at 1 mmol/L (which only inhibits calcium-activated K channels), barium at 20 micromol/L (which only inhibits inward rectifier K channels) and glyburide at 5 micromol/L (which only inhibits ATP-sensitive K channels) did not alter this relaxation. Finally, MF failed to relax contractions produced by elevations of extracellular K to levels high enough to abolish the K gradient across arterial SMC membranes. Thus, acute relaxation of rat tail arterial smooth muscle by MF may be dependent on the transmembrane K gradient and mediated at least in part by specific activation of K efflux through 4AP-sensitive voltage-dependent K channels in arterial SMC membranes.
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MESH Headings
- 4-Aminopyridine/pharmacology
- Animals
- Arteries/drug effects
- Arteries/innervation
- Arteries/metabolism
- Arteries/physiology
- Dose-Response Relationship, Drug
- Female
- Hypoglycemic Agents/antagonists & inhibitors
- Hypoglycemic Agents/pharmacology
- In Vitro Techniques
- Metformin/antagonists & inhibitors
- Metformin/pharmacology
- Muscle Contraction/drug effects
- Muscle Relaxation/drug effects
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/innervation
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiology
- Phenylephrine/antagonists & inhibitors
- Phenylephrine/pharmacology
- Potassium Channel Blockers
- Potassium Channels/physiology
- Rats
- Rats, Sprague-Dawley
- Tail/blood supply
- Vasoconstrictor Agents/pharmacology
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Affiliation(s)
- J D Peuler
- Department of Pharmacology, Midwestern University, Downers Grove, IL 60515, USA.
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Abe J, Ushijima C, Hizukuri S. Expression of the isoamylase gene of Flavobacterium odoratum KU in Escherichia coli and identification of essential residues of the enzyme by site-directed mutagenesis. Appl Environ Microbiol 1999; 65:4163-70. [PMID: 10473430 PMCID: PMC99755 DOI: 10.1128/aem.65.9.4163-4170.1999] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The isoamylase gene from Flavobacterium odoratum KU was cloned into and expressed in Escherichia coli JM109. The promoter of the gene was successful in E. coli, and the enzyme produced was excreted into the culture medium, depending on the amount of the enzyme expressed. The enzyme found in the culture medium showed almost the same M(r), heat-inactivating constant, and N-terminal sequence as those of the enzyme accumulated in the periplasmic space. This result indicated that the enzyme accumulated in an active form at the periplasm was transported out of the cell. The primary sequence of the enzyme, which was deduced from its nucleotide sequence, showed that the mature enzyme consisted of 741 amino acid residues. By changing five possible residues to Ala independently, it was found that Asp-374, Glu-422, and Asp-497 were essential. The sequences around those residues were highly conserved in isoamylases of different origins and the glycogen operon protein X, GlgX. The comparison of the distance between these essential residues with those of various amylases suggested that the bacterial and plant isoamylase but not GlgX had a longer fourth loop than the other amylases. This longer fourth loop had a possible role in accommodating the long branched chains of native glycogens and starches.
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Affiliation(s)
- J Abe
- Department of Biochemical Science and Technology, Faculty of Agriculture, Kagoshima University, Korimoto-1-21-24, Kagoshima 890, Japan.
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Lee JM, Peuler JD. Acute vasorelaxant effects of metformin and attenuation by stimulation of sympathetic agonist release. Life Sci 1999; 64:PL57-63. [PMID: 10027762 DOI: 10.1016/s0024-3205(98)00563-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We recently discovered 1) that intravenous injection of the antidiabetic drug metformin in the rat rapidly reduces arterial pressure elevations maintained by the alpha-adrenoceptor agonist phenylephrine (PE) and 2) that direct administration of metformin to isolated rat tail arterial tissue rings rapidly relaxes PE-induced contractions. To further characterize this potential direct vasodilator action, we examined effects of metformin on contractions induced not only by PE but also by norepinephrine (NE) and by nonadrenergic agonists (5-hydroxytryptamine, 5HT; arginine vasopressin, AVP). Also, because the rat tail artery contains abundant adrenergic nerve endings we conducted these tests not only in arterial rings with nerve endings intact but in rings in which they had been removed by pretreatment with 6-hydroxydopamine. In intact rings, metformin at levels from approximately 0.2 to 20 mmol/L rapidly relaxed half-maximal contractions induced by PE and NE similarly and to a markedly greater degree than contractions induced by 5-HT (p<0.05). Metformin did not relax AVP-induced contractions. In addition, removal of adrenergic nerve endings facilitated metformin's relaxant effects (p<0.05). Thus, the acute vasodilator action of metformin appears 1) to be selectively more powerful on arterial smooth muscle contractions induced adrenergically versus nonadrenergically and 2) to be buffered by a possible metformin-induced release of endogenous NE from adrenergic nerve endings. Such results were not seen during relaxation produced by either the calcium channel inhibitor nifedipine or the nitrovasodilator nitroprusside suggesting that metformin's effects are mediated by other mechanisms.
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Affiliation(s)
- J M Lee
- Department of Pharmacology, Midwestern University, Downers Grove, IL 60515, USA
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O'Shea MG, Morell MK. High resolution slab gel electrophoresis of 8-amino-1,3, 6-pyrenetrisulfonic acid (APTS) tagged oligosaccharides using a DNA sequencer. Electrophoresis 1996; 17:681-6. [PMID: 8738327 DOI: 10.1002/elps.1150170410] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A novel electrophoretic method for the analysis of oligosaccharides using DNA sequencer technology is illustrated using malto-oligosaccharide distributions obtained following isoamylase digestion of glycogen, wheat starch and potato starch. The debranched starches were derivatized at the reducing and with the charged fluorophore 8-amino-1,3,6-pyrenetrisulfonic acid (APTS). This highly reproducible method provides baseline resolution of oligomers from chain lengths of 3 to more than 80 glucose units, and exhibits high sensitivity with detection thresholds of one femtomole per resolved band. In addition, the reductive amination procedure attaches a single fluorophore per oligosaccharide, allowing calculation of the results on either a mass or a molar basis. The efficacy of the method is illustrated through the determination of the profile of individual oligosaccharides of chain length with a degree of polymerization (DP) < 80, derived from loading less than 15 ng per analysis of glycogen, wheat and potato starches. While the results obtained were superior in resolution and sensitivity to previously reported observations using a range of techniques, they were nonetheless consistent with the overall differences between these polysaccharides. The resolution, sensitivity, reproducibility and high throughput of the method provides substantial advantages over existing methods for the analysis of linear oligosaccharide chain length distributions.
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Affiliation(s)
- M G O'Shea
- Cooperative Research Centre for Plant Science, Canberra, ACT, Australia.
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Hizukuri S, Kozuma T, Yoshida H, Abe J, Takahashi K, Yamamoto M, Nakamura N. Properties ofFlavobacterium odoratum KU Isoamylase. STARCH-STARKE 1996. [DOI: 10.1002/star.19960480713] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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11
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Kim CH, Kim YS. Substrate specificity and detailed characterization of a bifunctional amylase-pullulanase enzyme from Bacillus circulans F-2 having two different active sites on one polypeptide. EUROPEAN JOURNAL OF BIOCHEMISTRY 1995; 227:687-93. [PMID: 7532585 DOI: 10.1111/j.1432-1033.1995.tb20189.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Bacillus circulans F-2 amylase-pullulanase enzyme (APE) displayed dual activity with respect to glycosidic bond cleavage. The enzyme was active on alpha-1,6 bonds in pullulan, amylopectin, and glycogen, while it showed alpha-1,4 activity against malto-oligosaccharides, amylose, amylopectin, and soluble starch, but not pullulan. Kinetic analysis of the purified enzyme in a system which contained both pullulan and amylose as two competing substrates was used to distinguish the dual specificity of the enzyme from the single-substrate specificity known for pullulanases and alpha-amylases. Enzyme activities were inhibited by some metal ions, and by metal-chelating agents with a different mode. The enzyme-inhibitory results of amylase and pullulanase with Hg2+ and Co2+ ions were different, indicating that the activation mechanisms of both enzyme activities are different. Cyclomaltoheptaose inhibited both alpha-amylase and pullulanase activities with inhibition constants (Ki) of 0.029 and 0.06 mg/ml, respectively. Modification with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide confirmed a carboxy group at the active sites of both enzymes. The N-terminal sequence of the enzyme was: Ala-Asp-Ala-Lys-Lys-Thr-Pro- Gln-Gln-Gln-Phe- Asp-Ala-Leu-Trp-Ala-Ala-Gly-Ile-Val-Thr-Gly-Thr-Pro-Asp-Gly-Phe. The purified enzyme displayed Michaelis constant (Km) values of 0.55 mg/ml for amylose, and 0.71 mg/ml for pullulan. When both amylose and pullulan were simultaneously present, the observed rate of product formation closely fitted a kinetic model in which the two substrates are hydrolyzed at different active sites. These results suggest that amylopullulanases, which possess both alpha-1,6 and alpha-1,4 cleavage activities at the same active site, should be distinguished from APEs, which contain both activities at different active sites on the same polypeptide. Also, it is proposed that the Enzyme Commission use the term 'amylase-pullulanase enzyme' to refer to enzymes which act on starch and cleave both alpha-1,6-bonds in pullulan and alpha-1,4 bonds in amylose at different active sites.
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Affiliation(s)
- C H Kim
- Laboratory of Molecular and Cellular Biology, Korea Institute of Science and Technology, Yusung, Taejon
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12
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Expression of Pseudomonas amyloderamosa isoamylase gene in Escherichia coli using an inducible T7 phage expression system. Process Biochem 1995. [DOI: 10.1016/0032-9592(94)00051-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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13
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Fang TY, Lin LL, Hsu WH. Recovery of isoamylase from Pseudomonas amyloderamosa by adsorption-elution on raw starch. Enzyme Microb Technol 1994. [DOI: 10.1016/0141-0229(94)90050-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Lomako J, Lomako WM, Whelan WJ. The substrate specificity of isoamylase and the preparation of apo-glycogenin. Carbohydr Res 1992; 227:331-8. [PMID: 1499031 DOI: 10.1016/0008-6215(92)85082-b] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A new facet of the specificity of the glycogen-debranching enzyme, isoamylase, namely, the hydrolysis of a carbohydrate-amino acid linkage, is described. This bond joins the terminal, reducing-end D-glucose unit of glycogen to the hydroxyl group of tyrosine in glycogenin, the primer protein for glycogen biogenesis. The specificity was further defined by demonstrating that 4-nitrophenyl alpha-maltotrioside and higher homologs also act as substrates. The splitting of the glycogen-glycogenin bond by isoamylase indicates the alpha-anomeric configuration of the terminal D-glucose unit. It also provides a means of preparing apo-glycogenin. Pullulanase, a somewhat similar starch- and glycogen-debranching enzyme, does not split these new isoamylase substrates, permitting the 4-nitrophenyl saccharides to be used in distinguishing between isoamylase and pullulanase.
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Affiliation(s)
- J Lomako
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Florida 33101
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Abstract
We recently reported that muscle contains a trichloroacetic acid-precipitable component having Mr approx. 400 kDa that can be glucosylated by an endogenous enzyme acting on UDPglucose. This component contains within itself the autocatalytic, self-glucosylating protein glycogenin, the primer for glycogen synthesis. We now report that this substance, to which we give the name proglycogen, is a glycogen-like molecule constituting about 15% of total glycogen. It acts as a very efficient acceptor of glucose residues added from UDPglucose. Further, that the endogenous enzyme that adds the glucose to proglycogen is not the autocatalytic protein but a glycogen synthase-like enzyme. Proglycogen may be an intermediate in the synthesis and degradation of macromolecular glycogen and may exist and be metabolized as a separate entity. Consideration should now be given to the revival of the concept that tissue contains two forms of glycogen. One is proglycogen. The other is the 'classical', macromolecular glycogen. Additionally, proglycogen and glycogen may be glucosylated by different forms of synthase.
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Affiliation(s)
- J Lomako
- Department of Biochemistry and Molecular Biology, University of Miami, FL 33101
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Affiliation(s)
- P C Calder
- Department of Biochemistry, University of Oxford, England
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Chen JH, Chen ZY, Chow TY, Chen JC, Tan ST, Hsu WH. Nucleotide sequence and expression of the isoamylase gene from an isoamylase-hyperproducing mutant, Pseudomonas amyloderamosa JD210. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1087:309-15. [PMID: 2248978 DOI: 10.1016/0167-4781(90)90004-l] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The isoamylase gene (ISO) of Pseudomonas amyloderamosa JD210, an isoamylase-hyperproducing mutant, was cloned in an isoamylase-deficient and transformable mutant strain K31. By deletion analysis, the ISO gene was found to be located within a 3.3 kilobases BamHI fragment. Its nucleotide sequence contained an open reading frame of 2328 nucleotides (776 amino acids) encoding a secreted isoamylase precursor. The ISO gene fragment was inserted into plasmids pKT230 and pBR 322 in opposite orientations. The expression of the ISO gene in the constructed plasmids was compared in P. amyloderamosa K31, Pseudomonas aeruginosa PAO1-161, Pseudomonas putida mt-2 and Escherichia coli HB101. In all transformed cells, the majority of the isoamylase produced was secreted and higher isoamylase activities were obtained in transformats with the transcriptional direction of the ISO gene similar to the nearby drug-determinant gene of the vector.
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Affiliation(s)
- J H Chen
- Culture Collection and Research Center, Food Industry Research and Development Institute, Hsinchu, Taiwan, China
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Kusano S, Takahashi S, Fujimoto D, Sakano Y. Effects of reduced malto-oligosaccharides on the thermal stability of pullulanase from Bacillus acidopullulyticus. Carbohydr Res 1990; 199:83-9. [PMID: 1696171 DOI: 10.1016/0008-6215(90)84095-c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We investigated the effects of the reduced malto-oligosaccharides, D-glucitol (G1-OH), maltitol (G2-OH), maltotriitol (G3-OH), maltotetraitol (G4-OH), and maltopentaitol (G5-OH) on the thermal stability of Bacillus acidopullulyticus pullulanase (EC 3.2.1.41). The thermal stability depended on the concentration of D-glucitol; after heat treatment for 90 min at 60 degrees in the presence of 0.56, 0.28, 0.14, or 0M G1-OH, the residual activity was 100, 80, 32, and 10% of the control, respectively. Stability increased with the number of glucosyl residues in the alditols added; the effects of G3-OH, G4-OH, and G5-OH on stability were remarkable. Addition of 30% G2-OH, G3-OH, and G4-OH also contributed to the thermal stability of the pullulanase immobilized onto chitosan beads treated with glutaraldehyde. A high concentration of G2-OH stabilized other debranching amylases, Klebsiella pneumoniae pullulanse, Bacillus sectorramus pullulanase, and Pseudomonas amyloderamosa isoamylase (EC 3.2.1.68) under heat treatment for 48 h at 60 degrees, as well as the pullullanase of B. acidopullulyticus.
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Affiliation(s)
- S Kusano
- Department of Agricultural Chemistry, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Japan
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Abstract
Starch-degrading, amylolytic enzymes are widely distributed among microbes. Several activities are required to hydrolyze starch to its glucose units. These enzymes include alpha-amylase, beta-amylase, glucoamylase, alpha-glucosidase, pullulan-degrading enzymes, exoacting enzymes yielding alpha-type endproducts, and cyclodextrin glycosyltransferase. Properties of these enzymes vary and are somewhat linked to the environmental circumstances of the producing organisms. Features of the enzymes, their action patterns, physicochemical properties, occurrence, genetics, and results obtained from cloning of the genes are described. Among all the amylolytic enzymes, the genetics of alpha-amylase in Bacillus subtilis are best known. Alpha-Amylase production in B. subtilis is regulated by several genetic elements, many of which have synergistic effects. Genes encoding enzymes from all the amylolytic enzyme groups dealt with here have been cloned, and the sequences have been found to contain some highly conserved regions thought to be essential for their action and/or structure. Glucoamylase appears usually in several forms, which seem to be the results of a variety of mechanisms, including heterogeneous glycosylation, limited proteolysis, multiple modes of mRNA splicing, and the presence of several structural genes.
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Affiliation(s)
- M Vihinen
- Department of Biochemistry, University of Turku, Finland
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23
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Ward OP, Moo-Young M. Enzymatic degradation of cell wall and related plant polysaccharides. Crit Rev Biotechnol 1989; 8:237-74. [PMID: 2650883 DOI: 10.3109/07388558909148194] [Citation(s) in RCA: 68] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Polysaccharides such as starch, cellulose and other glucans, pectins, xylans, mannans, and fructans are present as major structural and storage materials in plants. These constituents may be degraded and modified by endogenous enzymes during plant growth and development. In plant pathogenesis by microorganisms, extracellular enzymes secreted by infected strains play a major role in plant tissue degradation and invasion of the host. Many of these polysaccharide-degrading enzymes are also produced by microorganisms widely used in industrial enzyme production. Most commerical enzyme preparations contain an array of secondary activities in addition to the one or two principal components which have standardized activities. In the processing of unpurified carbohydrate materials such as cereals, fruits, and tubers, these secondary enzyme activities offer major potential for improving process efficiency. Use of more defined combinations of industrial polysaccharases should allow final control of existing enzyme processes and should also lead to the development of novel enzymatic applications.
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Affiliation(s)
- O P Ward
- Department of Biology, University of Waterloo, Ontario, Canada
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25
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Tao BY, Reilly PJ, Robyt JF. Neisseria perflava amylosucrase: characterization of its product polysaccharide and a study of its inhibition by sucrose derivatives. Carbohydr Res 1988; 181:163-74. [PMID: 2974759 DOI: 10.1016/0008-6215(88)84032-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Neisseria perflava amylosucrase forms from sucrose a polysaccharide very similar to glycogen, except that a larger proportion of its D-glucosyl residues are in short branches. Iodine staining of samples taken during polysaccharide formation indicate that the initial product is less branched than that formed at longer times. This glycogen-like polysaccharide has an estimated molecular mass range of 1 MD to 20 MD. Sucrose derivatives modified at C-3 (3-deoxysucrose and alpha-D-allopyranosyl beta-D-fructofuranoside), C-6 (6-deoxysucrose and 6-deoxy-6-fluorosucrose), and both C-4 and C-6 (4,6-dideoxysucrose) were tested as inhibitors of amylosucrase. Derivatives modified at C-6 were potent competitive inhibitors, with Ki values of 6.2 +/- 0.3 mM (6-deoxysucrose) and 0.50 +/- 0.06 mM (6-deoxy-6-fluorosucrose). The KM value of sucrose is 26.5 +/- 4.6 mM. Sucrose derivatives modified at C-3 were not significantly inhibitory over the concentration range tested. 4,6-Dideoxysucrose gave an unusual, non-competitive inhibition, in that, increasing its concentration did not produce a commensurate increase in the level of inhibition, which instead appeared to approach a limit. None of these sucrose derivatives was a substrate for amylosucrase, nor were they glycosyl donors to maltotriose.
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Affiliation(s)
- B Y Tao
- Department of Chemical Engineering, Iowa State University, Ames 50011
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26
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Amemura A, Chakraborty R, Fujita M, Noumi T, Futai M. Cloning and nucleotide sequence of the isoamylase gene from Pseudomonas amyloderamosa SB-15. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(19)76535-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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27
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Plant AR, Clemens RM, Morgan HW, Daniel RM. Active-site- and substrate-specificity of Thermoanaerobium Tok6-B1 pullulanase. Biochem J 1987; 246:537-41. [PMID: 3500710 PMCID: PMC1148306 DOI: 10.1042/bj2460537] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Thermoanaerobium Tok6-B1 pullulanase (EC 3.2.1.41) was active on alpha 1-6-glucosidic linkages of pullulan, amylopectin and glycogen and the alpha 1-4 linkages of amylose, amylopectin and glycogen but not of pullulan. Hydrolysis of short-chain-length malto-oligosaccharides (seven or fewer glucose residues) yielded maltose as product. Pullulan hydrolysis was pH-dependent and a plot of log(V/Km) versus pH implied a carboxy group with pKa 4.3 at the active site. Modification with 1-(3-dimethylaminopropyl)-3-ethylcarbodi-imide (EDAC) confirmed this view, and analysis of the order of reaction and inactivation kinetics suggested the presence of a single carboxy group at a catalytic centre of the active site. EDAC-mediated inhibition of pullulan alpha 1-6-bond hydrolysis was relieved by amylose or pullulan. Similarly both pullulan and amylose protected the activity directed at alpha 1-4 bonds of amylose from EDAC inhibition. When both amylose and pullulan were simultaneously present, the observed rate of product formation closely fitted a kinetic model in which both substrates were hydrolysed at the same active site.
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Affiliation(s)
- A R Plant
- Microbial Biochemistry and Biotechnology Unit, School of Science, University of Waikato, Private Bag, Hamilton, New Zealand
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28
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Gidley MJ, Bulpin PV. Crystallisation of malto-oligosaccharides as models of the crystalline forms of starch: minimum chain-length requirement for the formation of double helices. Carbohydr Res 1987. [DOI: 10.1016/s0008-6215(00)90086-7] [Citation(s) in RCA: 328] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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29
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Harada T. Isoamylase and its Industrial Significance in the Production of Sugars from Starch. Biotechnol Genet Eng Rev 1984. [DOI: 10.1080/02648725.1984.10647780] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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30
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Palmer TN, Macaskie LE, Grewel KK. The unit-chain distribution profiles of branched (1→4)-α- d -glucans. Carbohydr Res 1983. [DOI: 10.1016/0008-6215(83)88205-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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31
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Spencer-Martins I. Extracellular Isoamylase Produced by the Yeast
Lipomyces kononenkoae. Appl Environ Microbiol 1982; 44:1253-7. [PMID: 16346143 PMCID: PMC242182 DOI: 10.1128/aem.44.6.1253-1257.1982] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A strain of the starch-converting yeast
Lipomyces kononenkoae
produced, when grown on starch, a debranching enzyme that proved to be an isoamylase (glycogen 6-glucanohydrolase; E.C. 3.2.1.68). So far, only bacteria have been found to produce extracellular isoamylases. The yeast isoamylase enhanced β-amylolysis of amylopectin and glycogen and completely hydrolyzed these substrates into maltose when combined with a β-amylase but had no action on dextran or pullulan. By isopropanol precipitation and carboxymethyl cellulose chromatography,
L. kononenkoae
isoamylase was partially purified from the supernatant of cultures grown on a mineral medium with soluble starch. Optimum temperature and pH for activity of the isoamylase were 30°C and 5.6. The molecular weight was around 65,000, and the pI was at pH 4.7 to 4.8. The
K
m
(30°C, pH 5.5) for soluble starch was 9 g liter
−1
.
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Affiliation(s)
- I Spencer-Martins
- Laboratory of Microbiology, Gulbenkian Institute of Science, 2781 Oeiras Codex, Portugal
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Boyer CD, Simpson EKG, Damewood PA. The Possible Relationship of Starch and Phytoglycogen in Sweet Corn. II. The Role of Branching Enzyme I. STARCH-STARKE 1982. [DOI: 10.1002/star.19820340304] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Sato HH, Park YK. Production of Maltose from Starch by Simultaneous Action of beta-Amylase and Flavobacterium Isoamylase. STARCH-STARKE 1980. [DOI: 10.1002/star.19800321008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Sato HH, Park YK. Purification and Characterization of Extracellular Isoamylase from Flavobacterium sp. STARCH-STARKE 1980. [DOI: 10.1002/star.19800320410] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
Isoamylase has been prepared by affinity chromatography of a commercial enzyme-preparation from a strain of Cytophaga (also known as a Flavobacterium or Polyangium). The enzyme was not very stable, but the stability could be improved by calcium ions. The enzyme had a very low but significant activity on pullulan and on alpha-dextrins having maltosyl side-chains. This observation, which is contrary to previous reports, has been related to the specificity of isoamylase and other bacterial debranching-enzymes.
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42
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Multiple forms of (1 → 4)-α-d-glucan, (1 → 4)-α-d-glucan-6- glycosyl transferase from developing zea mays L. Kernels. Carbohydr Res 1978. [DOI: 10.1016/s0008-6215(00)84492-4] [Citation(s) in RCA: 153] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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The requirement for a primer in the in vitro synthesis of polysaccharide by sweet-corn (1 → 4)-α-d-glucan syntrase. Carbohydr Res 1978. [DOI: 10.1016/s0008-6215(00)84485-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Carter J, Smith EE. Actions of glycogen synthase and phosphorylase of rabbit-skeletal muscle on modified glycogens. Carbohydr Res 1978; 61:395-406. [PMID: 417806 DOI: 10.1016/s0008-6215(00)84499-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The high reactivities exhibited by rabbit-muscle synthase and phosphorylase for unmodified glycogen-acceptors decrease progressively, presumably because of a large increase in apparent Km as the glycogen molecule is converted into its component maltosaccharide chains by the debranching enzyme, isoamylase. Elongation of the outer chains of glycogen acceptor also results in decreased reactivities of the two transglucosylases and this is shown, for phosphorylase acting in the direction of glucan synthesis, to be caused by a decrease in the Vmax of the reaction. A partial restoration of the degradative reactivity of phosphorylase by a limited alpha-amylolysis of the long outer-chains of modified glycogen suggests a role of cytoplasmic alpha-amylase in mammalian glycogen metabolism.
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Kainuma K, Kobayashi S, Harada T. Action of Pseudomonas isoamylase on various branched oligo and poly-saccharides. Carbohydr Res 1978; 61:345-57. [PMID: 348322 DOI: 10.1016/s0008-6215(00)84494-8] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Pseudomonas isoamylase (EC 3.2.1.68) hydrolyzes (1 linked to 6)-alpha-D-glucosidic linkages of amylopectin, glycogen, and various branched dextrins and oligosaccharides. The detailed structural requirements for the substrate are examined qualitatively and quantitatively in this paper, in comparison with the pullulanase of Klebsiella aerogenes. As with pullulanase, Ps. isoamylase is unable to cleave D-glucosyl stubs from branched saccharides. Ps. isoamylase differs from pullulanase in the following characteristics: (1) The favored substrates for Ps. isoamylase are higher-molecular-weight polysaccharides. Most of the branched oligosaccharides examined were hydrolyzed at a lower rate, 10% or less of the rate of hydrolysis of amylopectin. (2) Maltosyl branches are hydrolyzed off by Ps. isoamylase very slowly in comparison with maltotriosyl branches. (3) Ps. isoamylase requires a minimum of three D-glucose residues in the B- or C-chain.
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Cheng KJ, Brown RG, Costerton JW. Characterization of a Cytoplasmic Reserve Glucan from
Ruminococcus albus. Appl Environ Microbiol 1977; 33:718-24. [PMID: 16345231 PMCID: PMC170749 DOI: 10.1128/aem.33.3.718-724.1977] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ruminococcus albus
, an anaerobic bacterium that digests cellulose in the rumen of cattle, produces intracellular polysaccharide granules varying from 0.05 to 0.31 μm in diameter when grown in batch culture. This polysaccharide material was purified and found to contain
d
-glucose as the only reducing sugar. The polyglucose polymer was slightly opalescent in aqueous solution and formed a strong reddish purple iodine complex with a maximum absorbance at 550 nm. Its infrared spectrum had characteristic absorption bands at 8.70, 9.25, and 9.75 μm and was identical with that of the amylopectin-glycogen type of
Megasphaera elsdenii
and that of the glycogen of enteric bacteria and beef liver. It reacted strongly with concanavalin A. Methylation analysis showed that the glucan contained 2,3,4,6-tetra-
O
-MeG-2,3,6-Tri-
O
-MeG-2,3-Di-
O
-MeG in a ratio of 8:84:8. Characterization of the products obtained by treatment with isoamylase indicates that the glucan of
R. albus
is of the glycogen type.
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Affiliation(s)
- K J Cheng
- Research Station, Agriculture Canada, Lethbridge, Alberta, Canada T1J 4B1
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Mercier C, Vernier JM. [The fine structure of trout liver glycogen]. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1977; 58:397-9. [PMID: 318273 DOI: 10.1016/0305-0491(77)90188-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
1. The fine structure of trout liver glycogen has been investigated using an enzymatic method. 2. The total conversion of glycogen into glucose under the action of amyloglucosidase and the percentage of beta-amylolysis before (37.4%) and after (97.8%) isoamylase debranching are similar to the mammalian glycogen. 3. However, the resistance to beta-amylase of certain debranched material leads to an hypothesis during glycogenolysis.
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Affiliation(s)
- C Mercier
- Institut National de la Recherche Agronomique, Centre de Recherches de Nantes, Nantes, France
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