Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1984 [Alpha]-Amylase action and 13C-nmr studies on amylose-V complexes and retrograded amylose Jay-lin Jane Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Biochemistry Commons Recommended Citation Jane, Jay-lin, "[Alpha]-Amylase action and 13C-nmr studies on amylose-V complexes and retrograded amylose" (1984). Retrospective Theses and Dissertations. 7768. https://lib.dr.iastate.edu/rtd/7768 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. 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Univer^ Micrdfîlms Irtenaticml 300 N. Zeeb Road Ann Arbor, Ml 48106 8423714 Jane, Jay-lin ALPHA-AMYLASE ACTION AND CARBON-13 NMR STUDIES ON AMYLOSE-V COMPLEXES AND RETROGRADED AMYLOSE Iowa State University PH.D. 1984 University Microfilms I ntGrnStion&1 300 N. Zeeb Road, Ann Arbor, Ml 48106 a-Amylase action and '^C-n.m.r. studies on amy1ose-V complexes and retrograded amylose by Jay-11n Jane A Dissertation Submitted to the Graduate Faculty in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY Department; Biochemistry and Biophysics Major: Biochemistry Approved: Signature was redacted for privacy. In C^rge of Maj6t^ Wc^k Signature was redacted for privacy. For the' Major Department Signature was redacted for privacy. For the Graduats^ol 1 ege Iowa State University Ames, Iowa 1984 i i TABLE OF CONTENTS Page ABBREVIATIONS USED v GENERAL INTRODUCTION I Explanation of dissertation format 3 LITERATURE REVIEW 4 Amylose: separation, physical properties, and conformât î on 4 Amylose-V complexes 5 Relationship of starch structure and retrograded amylose structure 9 a-Amylases 10 ^^C-Nuclear magnetic resonance spectroscopy 12 SECTION I STRUCTURE STUDIES OF AMYLOSE-V COMPLEXES AND RETROGRADED AMYLOSE BY ACTION OF a-AMYLASES AND A NEW METHOD OF PREPARING AMYLODEXTRINS 15 ABSTRACT 16 INTRODUCTION IB MATERIALS AND METHODS 19 Enzymes 19 Enzyme assay 19 Determination of the degree of polymerization (d.p.) of amylodextrin 20 Thin-layer chromatography 20 Column chromatography of reaction digests 20 Preparation of amylose 21 i 1 i Preparation of amylose-V complexes 21 Enzyme digests of amylose-V complexes 21 Preparation of retrograded amylose 22 Enzyme digests of retrograded amylose 23 Acid hydrolysis of retrograded amylose 23 X-Ray diffraction studies 23 RESULTS 24 DISCUSSION 40 ACKNOWLEDGMENTS 50 REFERENCES 51 SECTION II STUDY OF THE CONFORMATION OF AMYLOSE AND AMYLOSE-V COMPLEXES IN SOLUTION BY C-N.M.R. 53 ABSTRACT 54 INTRODUCTION 55 MATERIALS AND METHODS 57 Chemicals 57 Amylodextrin solutions 57 ^^C-Nuclear magnetic resonance spectroscopy 58 RESULTS 59 ^^C-N.m.r. spectra of aqueous solutions of potato amylose (d.p. 1000) and amylodextrin (d.p. 25) 59 ^^C-N.in.r. spectra of solutions of amy1odextrin-V complexes 59 ^^C-N.m.r. spectra of solutions of an amylodextrin extended- helix complex 67 Effect of helix to random-coil transition on ^^C-n.m.r. spectra of amylodextrin solutions 67 iv ^^C-N.m.r. spectra of methyl a-D-glucoside and methyl a-maltoside and their complexes with DMSO 72 ^^C-N.m.r. spectrum of retrograded amylodextrin 72 ^^C-N.m.r. spectra of amylodextrin in the presence of compounds that do not form complexes 72 ^^C-N.m.r. spectra of dextran solutions containing DMSO or ethanol 79 ^^C-N.m.r. spectra of aqueous solutions of cycloamyloses and their complexes with DMSO 79 DISCUSSION 85 ACKNOWLEDGMENTS 93 REFERENCES 94 GENERAL DISCUSSION _ 97 ACKNOWLEDGMENTS 103 REFERENCES 104 V ABBREVIATIONS USED A6 chemical shift change 6 chemical shift yg microgram m microliter limol micromole $ torsion angle about C^-O bond 4^ torsion angle about C^-O bond BSA Bac il lus subt il is a-amy1ase Cd+2 cadmium ion Carbons 1,2, ,6 carbon numbers designated for glucose residue at reducing end Carbons l',2',—,6' carbon numbers designated for glucose residue at non-reducing end C—n.m.r. carbon-13 nuclear magnetic resonance cm centimeter D^O deuterated water DMSO dimethy1 su1 fox i de DMSO-dg deuterated dimethyl sulfoxide d.p. degree of polymerization 2-D n.m.r. two-dimensional nuclear magnetic resonance EDB ethylene dibromide g gram h hour(s) ^H-n.m.r. proton-nuclear magnetic resonance vi H^O water HSA human salivary a-amylase tri iodide ion KBr potassium bromide KOH potassium hydroxide L liter mg milligram MHz megahertz min minute(s) mL milliliter mm millimeter molecular weight determined by the number of residues Mn^^ manganous ion N norma1ity nm nanometer FPA porcine pancreatic a-amylase ppm part(s) per million _2 SgOg thiosulfate ion t.l.c. thin layer chromatography v/v volume/volume 1 GENERAL INTRODUCTION Amylose, an a-l->-4 linked D-glucan, has a tendency to form helical complexes with many organic or inorganic chemicals. These helical com­ plexes behave differently than free amylose, and play an important role in scientific study and practical use. For example, the amylose-tri- iodide complex^ has been known for more than a century and a half; the deep blue color of the complex has led to its use as an indicator in iodine titrations. Formation of amylose complexes with dimethyl suIfox­ ide and potassium hydroxide has been commonly used as a method to dis­ solve otherwise insoluble amylose. The interaction of starch and fatty acids is believed to affect the texture of bakery products, and the grain fumigant, ethylene dibromide (EDB), may reside in grain products in a helical complex with starch. The helical complex of amylose with a collapsed helical structure, where the glucose residues in each turn of the helix are in contact with 2 glucose residues in adjacent turns, is called the amylose-V complex • The helical structure of the amylose-V complex was first reported in 1943 by Rundle and French^ following X-ray crystallographic studies. Since then, many other amylose-V complexes also have been studied by X-ray crystallography and/or electron microscopy. It has been suggested 4-7 that there are different diameters of amylose-V complexes, e.g., six , seven^ and eight^^ D-glucose residues per turn. However, because the X-ray diffraction patterns of amylose-V complexes, especially the fiber patterns, can be ambiguous, reports of the helix diameters are controversial. A different approach is necessary to confirm the repor­ 2 ted diameters. Electron-microscopic studies^'^'^^ show that amylose-V complexes with alcohols form crystalline lamellae in which helical seg­ ments, !0 nm in length, are stacked, so that the amorphous folding regions between helices are on the surfaces of the lamellae. a-Amy- lases, which are endohydrolases, were used in the present study to hydrolyze several lamellar amylose-V complexes. It was found that the a-amylases hydrolyze the amorphous folding regions, leaving the stacked helices in the interior of the lamellae intact. These amy1ase-resistant fragments were isolated and the chain lengths were analyzed to calculate the correct diameters of the helices. The same experiment was also conducted on retrograded amylose, which has been reported to have essen- 2 tially the same double-helical structure as native B-starch , to study its structure. Using a-amylases to hydrolyze amylose-V complexes and retrograded amylose, it is, thus, possible to prepare amylodextrins with different degrees of polymerization and with relatively narrow size dis­ tributions. X-Ray crystallography and electron microscopy can be used only to study the crystalline forms of the amylose-V complex. Heretofore, there has not been any known method for directly studying the structure of amylose-V complexes in solution.