Molecular Mechanism for the Regulation of Microcystin Toxicity to Protein Phosphatase 1 by Glutathione Conjugation Pathway.
Glutathione (GSH) conjugation was an important pathway to regulate the toxicity of microcystins (MCs) targeted to protein phosphatases. To explore the specific molecular mechanism for GSH detoxification, two typical MC-GSHs (derived from MCLR and MCRR) were synthesized, prepared, and purified according to previous research. Then, the reduced inhibition effect for MC-GSHs on protein phosphatase 1 was verified by comparing with their original toxins. To further clarify the molecular mechanism for MC-GSHs detoxification, we evaluated the interactions between MCs/MC-GSHs and PP1 with the assistance of MOE molecule simulation. When GSH was introduced to MCs, the covalent binding (Mdha7to Cys273), the hydrophobic interaction (Adda5with PP1), the hydrogen bonds (especially for Lys2-Arg96and Glu6-Tyr272), the covalent combination (between Mdha7and Cys273), and the ion bonds (between Mn2+and Asn124/His248/Asp64/His66) of MCLR/MCRR-PP1 complexes weakened to a certain extent, while the ion bonds between Mn2+and His173/Asp92residues increased. It was not difficult to find that the toxicity of MCs was closely related to the above sites/interactions and the above key information for MCs-PP1; MC-GSHs-PP1 complexes were important for clarifying the detoxification mechanism of MC-GSHs pathway. This study offers a comprehensive cognition on MCs toxicity regulation and provides valid theoretical support to control their potential risk.
College of Geography and Environment, Shandong Normal University, 88 East Wenhua Road, Jinan, Shandong 250014, China.
Wansong
0000-0003-1027-1464
W
Zong
College of Geography and Environment, Shandong Normal University, 88 East Wenhua Road, Jinan, Shandong 250014, China.
Xiaoning
X
Wang
College of Geography and Environment, Shandong Normal University, 88 East Wenhua Road, Jinan, Shandong 250014, China.
Yonggang
Y
Du
College of Geography and Environment, Shandong Normal University, 88 East Wenhua Road, Jinan, Shandong 250014, China.
Shuhan
S
Zhang
College of Geography and Environment, Shandong Normal University, 88 East Wenhua Road, Jinan, Shandong 250014, China.
Ying
Y
Zhang
School of Environmental and Civil Engineering, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China.
Yue
Y
Teng
D005978:Glutathione / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D006860:Hydrogen Bonding / Q000187:drug effects; D057927:Hydrophobic and Hydrophilic Interactions / Q000187:drug effects; D050217:Metabolic Detoxication, Phase II; D053858:Metabolic Networks and Pathways / Q000187:drug effects; D052998:Microcystins / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D054645:Protein Phosphatase 1 / Q000737:chemistry / Q000378:metabolism*
D052998:Microcystins; C078588:microcystin; D054645:Protein Phosphatase 1; D005978:Glutathione