New Karplus Equations for Conformational Analysis of Monosaccharides and Acetylated Derivatives

Poster Number

08C

Lead Author Major

Biochemistry

Lead Author Status

Junior

Second Author Major

Chemistry (Grad Student)

Third Author Major

Chemistry (Grad Student)

Fourth Author Major

Faculty Member

Format

Poster Presentation

Faculty Mentor Name

Andreas Franz

Faculty Mentor Department

Chemistry

Graduate Student Mentor Name

Amelia Watson

Graduate Student Mentor Department

Chemistry

Additional Mentors

Sven Hackbusch (s_hackbusch@u.pacific.edu) Dpt of Chemistry

Abstract/Artist Statement

Naturaloligosaccharidesare composed of multiplemonosaccharidesthat are linked viaglycosidicoxygen atom between carbon 1 (anomericcarbon) in one sugar and one of several carbons in the other sugar. A glycosidic linkage between carbon 1 and carbon 6 of two sugars results in greater flexibility because of the “arm-like” structure of the CH2OH group. The chemical linkage between sugars is characterized by dihedral (torsion) angles composed of 4 atoms in each case. Especially the so-called omega-angle, comprising Oglycosidic-C6-C5-C4, allows for greatest flexibility. Because of the complexity of the quantitative description of omega-angles inoligosaccharides, a simplified description of the omega-angle in non-substituted, free CH2OH groups ofmonosaccharidesis required. Evidence for the size of the dihedral angle in solution can be obtained from NMR-experiments and coupling constants (J-values). The experimental coupling values can be described in theory with a so-called Karplus plot that correlates J-values with the dihedral angle between the coupled nuclei. In this study, theoretical NMR calculations were carried out and torsional angles from MD-simulations were measured to construct Karplus plots for a- and ß-anomersofacetylatedandunacetylatedglucose, galactose, and mannose. Carbohydrates have numerous biochemical functions which include the storage of energy, functioning as structural components, immune responses to infection, “immunization” of babies through human milk, and protein folding. This variation in biochemical function is accredited to carbohydrates’ great structural diversity (constitutions and configurations). Because of the importance of carbohydrates, it is valuable to understand their function and specificity. Theoretical results compared very welltothe experimental results obtained inlab. Molecular modeling and dynamic simulation programs such as Spartan ’14, Gaussian ’09, and AMBER 14 (GLYCAM06 force field) were used to help calculate the NMR coupling constants. Preliminary data showed good fit between computed and experimental coupling constants in themonosaccharidesstudied.

Location

DeRosa University Center, Ballroom

Start Date

29-4-2017 1:00 PM

End Date

29-4-2017 3:00 PM

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Apr 29th, 1:00 PM Apr 29th, 3:00 PM

New Karplus Equations for Conformational Analysis of Monosaccharides and Acetylated Derivatives

DeRosa University Center, Ballroom

Naturaloligosaccharidesare composed of multiplemonosaccharidesthat are linked viaglycosidicoxygen atom between carbon 1 (anomericcarbon) in one sugar and one of several carbons in the other sugar. A glycosidic linkage between carbon 1 and carbon 6 of two sugars results in greater flexibility because of the “arm-like” structure of the CH2OH group. The chemical linkage between sugars is characterized by dihedral (torsion) angles composed of 4 atoms in each case. Especially the so-called omega-angle, comprising Oglycosidic-C6-C5-C4, allows for greatest flexibility. Because of the complexity of the quantitative description of omega-angles inoligosaccharides, a simplified description of the omega-angle in non-substituted, free CH2OH groups ofmonosaccharidesis required. Evidence for the size of the dihedral angle in solution can be obtained from NMR-experiments and coupling constants (J-values). The experimental coupling values can be described in theory with a so-called Karplus plot that correlates J-values with the dihedral angle between the coupled nuclei. In this study, theoretical NMR calculations were carried out and torsional angles from MD-simulations were measured to construct Karplus plots for a- and ß-anomersofacetylatedandunacetylatedglucose, galactose, and mannose. Carbohydrates have numerous biochemical functions which include the storage of energy, functioning as structural components, immune responses to infection, “immunization” of babies through human milk, and protein folding. This variation in biochemical function is accredited to carbohydrates’ great structural diversity (constitutions and configurations). Because of the importance of carbohydrates, it is valuable to understand their function and specificity. Theoretical results compared very welltothe experimental results obtained inlab. Molecular modeling and dynamic simulation programs such as Spartan ’14, Gaussian ’09, and AMBER 14 (GLYCAM06 force field) were used to help calculate the NMR coupling constants. Preliminary data showed good fit between computed and experimental coupling constants in themonosaccharidesstudied.