JKMRS Volume 19, No 2, pp 67-73;Isolation of Microcystin-LR an... | |
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2015년 10월 13일 / 조회수: 574 | |
Isolation of Microcystin-LR and Its
Potential Function of Ionophore Gilhoon Kim, Seungwon
Han, Hoshik Won* Department of Applied Chemistry, Hanyang University, 55,
Hanyang Daehak-Ro, Sangrok-Gu, Ansan 426-791, Korea Republic of Korea Received July 28, 2015; Revised
Sep 18, 2015; Accepted Sep 27, 2015 Abstract The
microcystin is a cyclic heptapeptide from metabolites of cyanobacteria in the
genera mycrocystis, anabaeba as a result of eutrophication. It has been known
that microcystin-LR is a potent inhibitor of the catalytic subunits of protein
phosphatase-1 (PP-1) as well as powerful tumor promoter. The active site of
microcystin actually has two metal ions Fe2+/Zn2+ close
to the nucleophilic portion of PP-1-microcystin complex. We
report the isolation and purification of this microcystin-LR from cyanobacteria
(blue-green algae) obtained from Daechung Dam in Chung-cheong Do, Korea.
Microcystin-LR was extracted from solid-phase extraction (SPE) sample
preparation using a CN cartridge. The cyanobacteria extract was purified to
obtain microcystin-LR by HPLC method and identified by LC/MS. The
detail structural studies that can elucidate the possible role of monovalent
and divalent metal ions in PP-1-microcystin complexation were carried out by utilizing
molecular dynamics. Conformational changes in metal binding for ligands were
monitored by molecular dynamic computation and potential of mean force (PMF)
using the method of the free energy perturbation. The microcystin-metal binding
PMF simulation results exhibit that microcystin can have very stable binding
free energy of -10.95 kcal/mol by adopting the Mg2+ ion at broad geometrical
distribution of 0.5~4.5Å, and show that
the K+ ion can form a stable metal complex rather than other
monovalent alkali metal ions. Keywords Microcystin-LR, Molecular dynamics,
Metal complex |
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