Development of Karplus Equations for 1→6-linked Disaccharides
Poster Number
12
Introduction/Abstract
In determining the solution structure of disaccharides, the glycosidic linkage, the connection between the sugars, is of particular interest.
Purpose
Precise knowledge about the glycosidic bond and its geometry allows us to describe the conformations of the compounds of interest. Based on data from Magnetic Resonance experiments (NMR) the Karplus equation gives the relationship between the nuclear coupling constant and dihedral angle of the coupled atoms.
Method
Experimental coupling constants were extracted from J-HMBC NMR data. A computational method for the development of Karplus equations that describe the glycosidic linkage is currently being developed. Compounds were first submitted to Spartan ’14 which resulted in a conformer distribution. Those conformers were submitted to Gaussian ’09 for optimization and a single point NMR calculation. The coupling constants (Hz) were extracted and fitted to the Karplus equation ( J = A*(cos (π*θ))2 +B*(cos(π*θ))+C. Statistical distributions of dihedral angles (MD-simulation) and the computed Karplus equation were used to determine the weighted coupling constants for comparison with the experimental values.
Results
This method was used on several simple structures and preliminary data showed a good fit between the computed and experimental coupling constants. Future work will continue the development of this method and test it on 1→6-linked disaccharides.
Significance
The conformations of these type of compounds is important to describe as it influences their reactivity with and recognition by other biomolecules in essential processes in living organisms.
Location
DeRosa University Center, Stockton campus, University of the Pacific
Format
Poster Presentation
Development of Karplus Equations for 1→6-linked Disaccharides
DeRosa University Center, Stockton campus, University of the Pacific
In determining the solution structure of disaccharides, the glycosidic linkage, the connection between the sugars, is of particular interest.
