121st General Meeting of the KCS

Type Poster Presentation
Area Analytical Chemistry
Room No. Event Hall
Time 4월 19일 (목요일) 11:00~12:30
Code ANAL.P-289
Subject Isolation of Microcystin-LR from Cyanobacteria and Its Solution Structure Elucidation by 2D-NOESY Back-calculations
Authors JungEun Kim, GilHoon Kim, Hoshik Won1,*
Department of Applied Chemistry, Hanyang University, Korea
1Department of Chemical and Molecular Engineering, Hanyang University, Korea
Abstract The microcystins is a cyclic heptapeptides produced by diverse cyanobacteria. The formula for these compounds is cyclo[2,3-didehydro-N-methyl-Ala-D-Ala-L-X-erythro-3-methyl-β- D-Asp-L-Y-Adda-γ-D-Glu], where Adda is 3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4E,6E-dienoic acid, and X and Y are two of several common L-amino acids. These microcystins are powerful inducers of tumours and inhibit the serine/threonine phosphatases(PP-1 and PP-2A) for growth. Microcystin-LR associates with high molecular, liver cytosolic components. In this study, we isolated microcystin-LR from cyanobacteria(blue-green algae) obtained from Dae-cheong Dam. Microcystin-LR was extracted from purification by HPLC method and identified by LC-MS/MS and DAD detector. 1H-NMR and 2D-NMR(COSY, TOCSY, NOESY) experiments were accomplished in DMSO-d6 and signal assignment of microcystin-LR was made. The solution structure of this compound was investigated with use of 2D-NMR and distance information. The distance information between proton pairs was obtained by NOE cross peak intensities of NOESY spectrum. On the basis of these distance data, distance geometry and molecular dynamic were carried out to determine the tertiary structure of microcystin-LR. DG structure of microcystin-LR was low penalty value (0.1 to 0.2 Å), and the total RMSD obtained upon superposition of all atoms were in the range (0.3 to 0.6 Å).
E-mail kghpotter@naver.com